Quantum Beam Science doi: 10.3390/qubs8010009
Authors: Zechen Lan Yasunobu Arikawa Yuki Abe Seyed Reza Mirfayzi Alessio Morace Takehito Hayakawa Tianyun Wei Akifumi Yogo
The advance of laser-driven neutron sources (LDNSs) has enabled neutron resonance spectroscopy to be performed with a single shot of a laser. In this study, we describe a detection system of epithermal (∼eV) neutrons especially designed for neutron resonance spectroscopy. A time-gated photomultiplier tube (PMT) with a high cut-off ratio was introduced for epithermal neutron detection in a high-power laser experiment at the Institute of Laser Engineering, Osaka University. We successfully reduced the PMT response to the intense hard X-ray generated as a result of the interaction between laser light and the target material. A time-gated circuit was designed to turn off the response of the PMT during the laser pulse and resume recording the signal when neutrons arrive. The time-gated PMT was coupled with a 6Li glass scintillator, serving as a time-of-flight (TOF) detector to measure the neutron resonance absorption values of 182W and 109Ag in a laser-driven epithermal neutron generation experiment. The neutron resonance peaks at 4.15 eV of 182W and 5.19 eV of 109Ag were detected after a single pulse of laser at a distance of 1.07 m.
]]>Quantum Beam Science doi: 10.3390/qubs8010008
Authors: Fanni Juranyi Masako Yamada Christine Klauser Lothar Holitzner Uwe Filges
FOCUS is a direct-geometry cold neutron time-of-flight spectrometer at SINQ (PSI, CH). Its neutron guide was exchanged in 2019/2020 within the SINQ Upgrade project, while the rest of the instrument remained unchanged. The new guide provided a significant intensity increase across the whole spectrum, especially at short wavelengths, due to the more efficient transport and extended phase space of the transported neutrons. The practically available energy transfer range (at the neutron energy loss side) was increased to about 40 meV. The main reason for the intensity benefit at short incident wavelengths was the improved guide coating, whereas at long wavelengths it was the new ballistic shape. The interesting part of the guide is the “peanut shape” of the curved part in the horizontal plane. For this, we derived the analytical restriction on the geometry to avoid a direct line of sight from the source. The guide geometry and the supermirror coating were optimized using Mcoptimize, a particle swarm optimization routine employing Mcstas. Future ballistic neutron guides may profit from the presented approaches, optimization strategy, and results.
]]>Quantum Beam Science doi: 10.3390/qubs8010007
Authors: Pingguang Xu Shuyan Zhang Stefanus Harjo Sven C. Vogel Yo Tomota
Comprehensive information on in situ microstructural and crystallographic changes during the preparation/manufacturing processes of various materials is highly necessary to precisely control the microstructural morphology and the preferred orientation (or texture) characteristics for achieving an excellent strength–ductility–toughness balance in advanced engineering materials. In this study, in situ isothermal annealing experiments with cold-rolled 17Ni-0.2C (mass%) martensitic steel sheets were carried out by using the TAKUMI and ENGIN-X time-of-flight neutron diffractometers. The inverse pole figures based on full-profile refinement were extracted to roughly evaluate the preferred orientation features along three principal sample directions of the investigated steel sheets, using the General Structure Analysis System (GSAS) software with built-in generalized spherical harmonic functions. The consistent rolling direction (RD) inverse pole figures from TAKUMI and ENGIN-X confirmed that the time-of-flight neutron diffraction has high repeatability and statistical reliability, revealing that the principal preferred orientation evaluation of steel materials can be realized through 90° TD ➜ ND (transverse direction ➜ normal direction) rotation of the investigated specimen on the sample stage during two neutron diffraction experiments. Moreover, these RD, TD, and ND inverse pole figures before and after the in situ experiments were compared with the corresponding inverse pole figures recalculated from the MUSASI-L complete pole figure measurement and the HIPPO in situ microstructure evaluation, respectively. The similar orientation distribution characteristics suggested that the principal preferred orientation evaluation method can be applied to the in situ microstructural evolution of bulk orthorhombic materials and spatially resolved principal preferred orientation mappings of large engineering structure parts.
]]>Quantum Beam Science doi: 10.3390/qubs8010006
Authors: M. V. Shevelev A. S. Konkov S. R. Uglov B. A. Alekseev Yu. M. Cherepennikov
The high-intensity and monochromatic radiation sources in the water window spectral range are desirable for many applications. One of the potential candidates of soft X-ray sources is polarization radiation produced by a charged particle passing through a thin foil. In the soft X-ray range near the absorption edges of a target material, the real part of dielectric permittivity can exceed unity, and the Tamm–Frank criterion is fulfilled. Thus, two types of radiation are produced: transition and Cherenkov radiation. In this report, we theoretically investigated the spectral characteristics of radiation produced in both cases when the Tamm–Frank criterion is met or not met. We showed the dependences of the spectrum as a function of thickness and the incidence angle. To describe the properties of polarization radiation and the complex dielectric permittivity, the polarization current approach and Henke’s model were used, respectively.
]]>Quantum Beam Science doi: 10.3390/qubs8010005
Authors: L. Giuffrida V. Istokskaia A. Picciotto V. Kantarelou M. Barozzi R. Dell`Anna M. Divoky O. Denk D. Giubertoni F. Grepl A. Hadjikyriacou M. Hanus J. Krasa M. Kucharik T. Levato P. Navratil J. Pilar F. Schillaci S. Stancek M. Tosca M. Tryus A. Velyhan A. Lucianetti T. Mocek D. Margarone
An experimental platform for laser-driven ion (sub-MeV) acceleration and potential applications was commissioned at the HiLASE laser facility. The auxiliary beam of the Bivoj laser system operating at a GW level peak power (~10 J in 5–10 ns) and 1–10 Hz repetition rate enabled a stable production of high-current ion beams of multiple species (Al, Ti, Fe, Si, Cu, and Sn). The produced laser–plasma ion sources were fully characterized against the laser intensity on the target (1013–1015 W/cm2) by varying the laser energy, focal spot size, and pulse duration. The versatility and tuneability of such high-repetition-rate laser–plasma ion sources are of potential interest for user applications. Such a statistically accurate study was facilitated by the large amount of data acquired at the high repetition rate (1–10 Hz) provided by the Bivoj laser system.
]]>Quantum Beam Science doi: 10.3390/qubs8010004
Authors: Jelena Vesić Matjaž Vencelj
Small-scale facilities play a significant role in the landscape of nuclear physics research in Europe. They address a wide range of fundamental questions and are essential for teaching and training personnel in accelerator technology and science, providing them with diverse skill sets, complementary to large projects. The current status and perspectives of nuclear physics research at small-scale facilities in Europe will be given.
]]>Quantum Beam Science doi: 10.3390/qubs8010003
Authors: Wei Jiang Chaoxuan Lu Binyang Han Boxin Dai Qiang Zheng Guo Liu Jianxun Wang Yong Luo
The magnetron injection gun (MIG) is an essential component of the gyrotron traveling wave tube (gyro-TWT). Although the electron beam status influences the performance of the device, it cannot be measured directly in the experiment. An online evaluation module (OEM) for the experiment is developed to calculate the instant beam parameters of MIG. The OEM, by reconstructing the geometry of the MIG and related magnetic field distribution, can obtain the electron beam status under the operating parameters through the online simulation. The beam velocity spread of thermal emission with instant temperature and surface roughness are also considered. The validation is done in a W-band gyro-TWT, and the beam performance is evaluated in the experiment. With a pitch factor of 1.06 electron beam, the velocity spread affected by the electric-magnetic mismatch, thermal emission, and roughness is 1.00%, 0.56%, and 0.43%, respectively. The other beam parameters are also presented in the developed module. The OEM could guide and accelerate the testing process and ensure the safe and stable operation of the device.
]]>Quantum Beam Science doi: 10.3390/qubs8010002
Authors: Jessica Brocchieri Rosa Vitale Carlo Sabbarese
A sample of 18 double-relief coins from different poleis of Magna Graecia and ancient Italy has been analysed using a handheld XRF spectrometer directly inside the Museo Provinciale Campano (Capua, Italy). The data analysis shows that (i) the main elements are Ag and Cu, indicating that the coins are of high fineness (average Ag 95.7%), (ii) trace elements can help to characterise the coins, (iii) a superficial chemically altered layer (corrosion) is absent, (iv) the values of ratio Ag Kα/Lα evidence the presence of an enrichment layer on the surface of silver or subaerata in some coins. Multivariate statistical analysis and graph analysis allowed the coins to be assigned to different groups with the highest possible accuracy on the basis of the chemical data obtained and models to be constructed to classify the coins according to their historical periods.
]]>Quantum Beam Science doi: 10.3390/qubs8010001
Authors: Yasufumi Miura Kenji Suzuki Satoshi Morooka Takahisa Shobu
Probabilistic fracture mechanics (PFM) is increasingly recognized as a viable approach for evaluating the structural integrity of nuclear components, such as piping, primarily affected by stress corrosion cracking (SCC). PFM analysis requires several input parameters, among which welding residual stress is critically important due to its significant influence on SCC initiation and propagation. Recently, a novel technique involving a double-exposure method (DEM) utilizing synchrotron X-rays was introduced as an effective means for measuring welding residual stress with high spatial resolution. In this paper, we applied DEM to assess the residual stress of a plate specimen, which was extracted from a welded pipe through electrical discharge machining. Consequently, detailed stress maps under a plane stress state were generated. Additionally, the residual stress distributions in the welded pipe under a triaxial stress state were evaluated using neutron diffraction. Based on these findings, we proposed a methodology to acquire detailed stress maps of welded pipes by combining high-energy synchrotron X-rays and neutron diffraction.
]]>Quantum Beam Science doi: 10.3390/qubs7040037
Authors: Matthias Alfeld Philipp Tempel Volkert van der Wijk
The acquisition of elemental and chemical distribution images on the surface of cultural heritage objects has provided us new insights into our past. The techniques commonly employed, such as macroscopic X-ray fluorescence imaging (MA-XRF), in general require pointwise or whisk-broom scanning of an object under constant measurement geometry for optimal results. Most scanners in this field use stacked linear motorized stages, which are a proven solution for 2D sample positioning. Instead of these serial systems, we propose the use of a parallel cable robot to position the measurement head relative to the object investigated. In this article, we illustrate the significance of the issue and present our own cable robot prototype and test its capabilities, but also discuss the current shortcomings of the concept. With this, we demonstrate the potential of cable robots as platforms for MA-XRF and similar imaging techniques.
]]>Quantum Beam Science doi: 10.3390/qubs7040036
Authors: Almaz Nazarov Alexey Maslov Elena Korznikova Kamil Ramazanov
This article explores the utilization of cathodic-arc deposition Cr-Al overlay coatings as oxidation protection for Ti-Al-Nb intermetallic alloys. The primary objective is to investigate PVD Al-Cr coatings deposited via cathodic-arc deposition without subsequent vacuum annealing. The microstructure, phase, and chemical composition of the coatings were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analysis. Isothermal exposure of samples in a laboratory air furnace was conducted, revealing the efficacy of Cr-Al coatings in protecting the Ti49-11Al-40Nb-1.5Zr-0.75V-0.75Mo-0.2Si (mass%) intermetallic alloy VTI-4 against oxidation. The findings highlight that the as-deposited coatings possess a layered structure and contain Al-Cr intermetallics. Post-exposure to the furnace without prior vacuum annealing results in coatings exhibiting a porous microstructure, raising concerns regarding oxidation protection. This investigation of Cr-Al coatings on a VTI-4 alloy substrate yields valuable insights into their nanolaminate structure and challenges associated with aluminum droplet fractions. The proposed additional vacuum heat treatment at 650 °C for 500 h effectively homogenizes the coating, leading to predominant Cr2Al and Ti-Al phases. Additionally, the formation of diffusion layers at the “coating–substrate” interface and the presence of oxide barriers contribute to the coatings’ heat resistance. Our research introduces possibilities for tailoring coating properties for specific high-temperature applications in aerospace, energy, or industrial contexts. Further refinement of the heat treatment process offers the potential for developing advanced coatings with enhanced performance characteristics.
]]>Quantum Beam Science doi: 10.3390/qubs7040035
Authors: Andrew G. Manning Shinichiro Yano Sojeong Kim Won Bo Lee Soo-Hyung Choi Nicolas R. de Souza
Polarisation analysis for neutron scattering experiments is a powerful tool suitable for a wide variety of studies, including soft-matter samples which have no bulk magnetic behaviour and/or a significant hydrogen content. Here, we describe a method to leverage the versatility and spin-polarisation capabilities of a cold triple-axis spectrometer to perform a measurement to separate coherent and incoherent neutron scattering for a non-magnetic sample in the quasielastic neutron scattering (QENS) regime. Such measurements are complementary to unpolarised QENS measurements, which may typically be performed on a backscattering or time-of-flight spectrometer instrument where polarisation analysis can be significantly more difficult to achieve, and utilise the strengths of each type of instrument.
]]>Quantum Beam Science doi: 10.3390/qubs7040034
Authors: Shutaro Machiya Kozo Osamura Yoshimitsu Hishinuma Hiroyasu Taniguchi Stefanus Harjo Takuro Kawasaki
MgB2 represents a hexagonal superconductive material renowned for its straightforward composition, which has facilitated the development of cost-effective practical wires. Its capacity to function at temperatures as low as liquid hydrogen (LH2) has made it a prominent candidate as wire material for the coils of next-generation fusion reactors. Much like other superconducting wires, a prevalent issue arises when these wires are employed in coils, wherein electromagnetic forces induce tensile stress and strain within the wire. This, in turn, diminishes the critical current, which is the maximum current capable of flowing within the generated magnetic field and strain. The techniques and methods for accurately measuring the actual strain on the filaments are of paramount importance. While strain measurements have been conducted with synchrotron radiation and neutrons for other practical wires in the past, no such measurements have been undertaken for MgB2. Presumably, this lack of measurement is attributed to its relatively greater thickness, making it less suitable for synchrotron radiation measurements. Additionally, the high absorption cross-section of the included boron-10 poses challenges in obtaining elastic scattering data for neutron measurements. In response, we fabricated a wire enriched with boron-11, an isotope with a smaller neutron absorption cross-section. We then embarked on the endeavor to measure its strain under tensile loading using pulsed neutrons. Consequently, we succeeded in obtaining changes in the lattice constant under tensile loading through Rietveld analysis. This marks the inaugural instance of strain measurement on an MgB2 filament, signifying a significant milestone in superconductivity research.
]]>Quantum Beam Science doi: 10.3390/qubs7040033
Authors: Vladislav Ryzhkov Mikhail Zhuravlev Gennady Remnev
The collective acceleration of helium ions from its residual atmosphere in the Luce diode was studied at helium pressures from 0.13 to 0.23 Pa. The energy of accelerated ions was determined from the drift velocity of the virtual cathode accelerating the ions. The number of 4He was determined by radioactivities of 13N and 30P induced in h-BN and Al targets via the nuclear reactions 10B(α,n)13N and 27Al(α,n)30P. The efficiency of capturing 4He ions in collective acceleration from the residual helium atmosphere was estimated as 0.25%. With increasing helium pressure above 0.15 Pa, the energy of the main ion group noticeably decreased to 0.46 MeV/amu compared to the acceleration from a usual residual atmosphere (~0.6 MeV/amu); however, the probability of ion acceleration to a specific energy of up to 1.57 MeV/amu increased significantly. Such increases in the ion energy were accompanied by the appearance of the signal of the second virtual cathode 7–9 ns after the appearance of the first virtual cathode.
]]>Quantum Beam Science doi: 10.3390/qubs7040032
Authors: Stefanus Harjo Wu Gong Takuro Kawasaki
Tensile deformation in situ neutron diffraction of an extruded AZ31 alloy was performed to validate conventional procedures and to develop new procedures for stress evaluation from lattice strains by diffraction measurements of HCP-structured magnesium alloys. Increases in the lattice strains with respect to the applied true stress after yielding largely vary among [hk.l] grains. Some [hk.l] grains have little or no increase in lattice strain, making it difficult to use the conventional procedures to determine the average phase strain by using lattice constants or by averaging several lattice strains. The newly proposed procedure of stress evaluation from the lattice strains shows very high accuracy and reliability by weighting the volume fraction of [hk.l] grains and evaluating them in many [hk.l] orientations in addition to multiplication by the diffraction elastic constant. When multiple hk.l peaks cannot be obtained simultaneously, we recommend to use the 12.1 peak for stress evaluation. The lattice strain value evaluated from the 12.1 peak shows a good linear relationship with the applied true stress for the whole deformation region.
]]>Quantum Beam Science doi: 10.3390/qubs7040031
Authors: Akinori Takeyama Takahiro Makino Yasunori Tanaka Shin-Ichiro Kuroki Takeshi Ohshima
Silicon carbide junction field-effect transistors (SiC JFETs) are promising candidates as devices applicable to radiation conditions, such as the decommissioning of nuclear facilities or the space environment. We investigate the origin of the threshold volage (Vth) shift and hysteresis of differently structured SiC JFETs. A large positive Vth shift and hysteresis are observed for a depletion-type JFET with a larger depletion layer width. With changing the sweep range of the gate voltage and depletion width, the Vth shift was positively proportional to the difference between the channel depth and depletion width (channel depth–gate depletion width). By illuminating the sub-band gap light, the Vth of the irradiated depletion JFETs recovers close to nonirradiated ones, while a smaller shift and hysteresis are observed for the enhancement type with a narrower width. It can be interpreted that positive charges generated in a gate depletion layer cause a positive Vth shift. When they are swept out from the depletion layer and trapped in the channel, this gives rise to a further Vth shift and hysteresis in gamma-irradiated SiC JFETs.
]]>Quantum Beam Science doi: 10.3390/qubs7040030
Authors: Jessica Brocchieri Elvira Scialla Marianna Merolle Palma Maria Recchia Roberto della Rocca Carlo Sabbarese
A diagnostic analysis of the painting depicting San Patroba che predica ai fedeli di Pozzuoli by Massimo Stanzione was carried out. The painting was completed in 1635–1637 to decorate the choir of the Cathedral of Saint Procolo in Pozzuoli (Naples, Italy). The technique of X-ray fluorescence (XRF) and multispectral imaging were applied on site to learn about the executive technique, the palette of the painting, and the restoration works, as well as understand the influence of the other painters active in Naples in that period. The results of the research are presented and discussed to draw general aspects and peculiarities of the pigments and the pictorial technique used by this important painter, as well as the restorations.
]]>Quantum Beam Science doi: 10.3390/qubs7030029
Authors: Ilham Hamdi Alaoui Nathalie Lemée Françoise Le Marrec Moussa Mebarki Anna Cantaluppi Delphine Favry Abdelilah Lahmar
Bismuth sodium titanate (BNT) thin films were deposited on Pt/SiN substrates by Sol-Gel spin coating technique and annealed under O2 atmosphere. The microstructural, structural, and electrical properties of the obtained film were investigated. Electron microscopy scans and atomic force microscopy micrographs were used to analyze the microstructure of the films. Furthermore, energy-dispersive X-ray spectroscopy (EDX) analysis revealed a Na-deficient composition for the obtained film. X-ray diffraction and Raman spectroscopy allowed the identification of a pure perovskite BNT phase. Dielectric, ferroelectric, and leakage current measurements revealed good frequency stability of the dielectric constant and dielectric losses for BNT thin film. The results are discussed in terms of Na deficiency effects on the defect structure of BNT. Further, the film showed attractive electrostatic energy storage properties with energy density that exceeds 1.04 J/cm3 under E = 630 kV/cm.
]]>Quantum Beam Science doi: 10.3390/qubs7030028
Authors: Aslı Kuşoğlu Dimiter Loukanov Balabanski
The existing experimental data for the γ decay of the stable N=Z doubly-odd nuclei and the β decay of the corresponding isospin multiplets is reviewed. The structure of the lightest nuclei with masses A≤14 is used to test and constrain ab initio nuclear theories. Most of the data were obtained in the second half of the last century and, in some cases, lack the needed precision for comparison with theoretical calculations. Recent spectroscopic studies in the lightest doubly-odd N = Z nuclei are discussed, as well as open problems related to the understanding of their structures and ideas for future experiments.
]]>Quantum Beam Science doi: 10.3390/qubs7030027
Authors: Alexander Chernyaev Mikhail Belikhin Ekaterina Lykova Alexey Shcherbakov
Photons with energy totaling more than 10 MeV provide efficient treatment for deeply seated tumors but interact with the nuclei of high-Z materials constituting a head of the linac. These interactions result in photoneutrons that deliver an additional out-of-field dose to the patient, which increases the risk of radiation-induced cancer. Monte Carlo simulation is an accurate strategy for estimating the effective photoneutron dose for a patient. In the current study, the possibility of using GEANT4 to calculate the photoneutron spectrum from the medical linac was investigated. The free-in-air photoneutron spectrum from a head of the linac was simulated using the NeutronHP experimental package. Validation of the simulated model was carried out based on a comparison of simulated and measured percentage depth–dose curves from photons in the water phantom. The obtained photoneutron spectrum was compared with the previously measured spectrum at the Varian Thilogy linac. GEANT4 may improve the accuracy of calculations of the effective dose based on photoneutrons. However, the simulated model should be improved and optimized. In the future, this model may constitute a physical basis for the prediction of the risk of radiation-induced cancer at our clinical center.
]]>Quantum Beam Science doi: 10.3390/qubs7030026
Authors: C. Aris Chatzidimitriou-Dreismann
The conventional theory of neutron beams interacting with many-body systems treats the beam as a classical system, i.e., with its dynamical variables appearing in the quantum dynamics of the scattering process not as operators but only as c-numbers. Moreover, neutrons are described with plane waves, i.e., the concept of a neutron’s (finite) coherence length is here irrelevant. The same holds for electron, atom or X-ray scattering. This simplification results in the full decoupling of the probe particle’s dynamics from the quantum dynamics of the scatterer—a well-known fact also reflected in the standard formalism of time-correlation functions (see textbooks). Making contact with modern quantum-theoretical approaches (e.g., quantum entanglement, “which-path information” versus interference, von Neumann measurement, Weak Values (WV), etc.), new observable effects of non-relativistic quantum beam scattering may be exposed and/or predicted, for instance, a momentum-transfer deficit and an intensity deficit in neutron scattering from protons of hydrogen-containing samples. A new WV-theoretical treatment is provided, which explains both these “deficit effects” from first principles and on equal footing.
]]>Quantum Beam Science doi: 10.3390/qubs7030025
Authors: Marina V. Il’ina Soslan A. Khubezhov Maria R. Polyvianova Oleg I. Il’in Yuriy Dedkov
The chemical composition and stoichiometry of vertically aligned arrays of nitrogen-doped multi-walled carbon nanotubes (N-CNTs) were studied by photoelectron spectroscopy using laboratory and synchrotron X-ray sources. We performed careful deconvolution of high-resolution core-level spectra to quantify pyridine/pyrrole-like defects in N-CNTs, which are a key factor in the efficiency of the piezoelectric response for this material. It is shown that the XPS method makes it possible to estimate the concentration and type of nitrogen incorporation (qualitatively and quantitatively) in the “N-CNT/Mo electrode” system using both synchrotron and laboratory sources. The obtained results allow us to study the effect of the nickel catalytic layer thickness on the concentration of pyridine/pyrrole-like nitrogen and piezoelectric response in the nanotubes.
]]>Quantum Beam Science doi: 10.3390/qubs7030024
Authors: Aleksandra Leonidova Vladimir Aseev Denis Prokuratov Denis Jolshin Mikhail Khodasevich
The study of the chemical composition of historical glasses is widely used in archaeometry. The results of such analyses provide information on the probable date, place, and technological features of their production. Over time, a weathered layer may form on the surface of the glass, which differs in composition from the original one. To determine the initial composition using conventional methods (for example, X-ray fluorescence spectroscopy), the weathered layer should be removed. For historical objects, such manipulation is unacceptable and should be minimized. One of the methods for analyzing the chemical composition with minimal damage to a sample is laser-induced breakdown spectroscopy. The aim of this work was to develop a LIBS method, which makes it possible to perform a quantitative analysis of lead silicate glasses, including glasses containing a weathered layer. Reference glasses with a variable content of potassium, silicon, and lead oxides were synthesized, and based on the LIBS spectra, a calibration dependence was obtained that made it possible to measure the concentration of lead and potassium oxides in glasses within 70–85 and 5–20 wt%, respectively. The method was applied to analyze the composition of the glaze on a historic glazed tile from the burial church in the Euphrosinian monastery in Polotsk (the second half of the 12th century AD). The crater formed with the laser beam on the glazed surface was about 200 microns. Such damage is negligible compared to the total surface area of the tile (~10 cm2). The thickness of the weathered glaze layer was 70 microns, which was determined using variation in lead oxide content.
]]>Quantum Beam Science doi: 10.3390/qubs7030023
Authors: Yujiro Hayashi Hidehiko Kimura
Plastically deformed low-carbon steel has been analyzed by nondestructive three-dimensional orientation and strain mapping using scanning three-dimensional X-ray diffraction microscopy (S3DXRD). However, the application of S3DXRD is limited to single-phase alloys. In this study, we propose a modified S3DXRD analysis for dual-phase alloys, such as ferrite–pearlite carbon steel, which is composed of grains detectable as diffraction spots and a phase undetectable as diffraction spots. We performed validation experiments for ferrite–pearlite carbon steel with different pearlite fractions, in which the ferrite grains and the pearlite corresponded to the detectable grains and an undetectable phase, respectively. The regions of pearlite appeared more remarkably in orientation maps of the ferrite grains obtained from the carbon steel samples than that of the single-phase low-carbon steel and increased with the increase in the carbon concentration. The fractions of the detectable grains and the undetectable phase were determined with an uncertainty of 15%–20%. These results indicate that the proposed modified analysis is qualitatively valid for dual-phase alloys comprising detectable grains and an undetectable phase.
]]>Quantum Beam Science doi: 10.3390/qubs7030022
Authors: Petya Penkova Galina Malcheva Margarita Grozeva Tanya Hristova Georgy Ivanov Stefan Alexandrov Kiril Blagoev Vani Tankova Valentin Mihailov
In the presented work, a total of 60 bronze artefacts from the prehistoric settlement of Baley, Bulgaria were analyzed by means of laser-induced breakdown spectroscopy (LIBS) and X-ray fluorescence spectroscopy (XRF). The archaeological finds were excavated from three levels, with a time span from the 15th century BC to the first half of the 11th century BC. The obtained analytical information was used for quantitative estimation of the amount of tin, lead and arsenic, which determine the mechanical properties of the alloy and the manufacturing technology. Based on the estimated quantities of these elements, a chemometric statistical analysis (principal component analysis—PCA) was performed to classify and divide the samples into separate groups according to the production dating. The data obtained in this study can be used for comparison with the elemental content in deposits from other settlements of this period.
]]>Quantum Beam Science doi: 10.3390/qubs7030021
Authors: Heetae Kim Sungmin Jeon Yoochul Jung Juwan Kim
In this paper, the magnetic heating effect of the superconducting quarter-wave resonator (QWR) cavities is investigated, and the Q slopes of the superconducting cavities are measured with an increasing accelerating field. Bardeen–Cooper–Schrieffer (BCS) resistance is calculated for the zero-temperature limit. The vertical test is shown for the performance test of the QWR cavities. The parameters for the QWR cavity are presented. The Q slopes are measured as a function of an accelerating electric field at 4.2 K. The surface resistance of the superconducting cavity increases with an increasing peak magnetic field. The magnetic defects degrade the quality factor. From the magnetic degradation, we determine the magnetic moments of the superconducting cavities. All quarter-wave resonator (QWR) cryomodules are installed in the tunnel, and beam commissioning is performed successfully.
]]>Quantum Beam Science doi: 10.3390/qubs7020020
Authors: Leighanne C. Gallington Stephen K. Wilke Shinji Kohara Chris J. Benmore
The popularity of the pair distribution function (PDF) analysis of X-ray total scattering data has steadily grown as access to ex situ synchrotron data has expanded. Due to the broadening of the PDF user community, there is a growing demand for software that can be used to extract PDFs and is accessible to non-expert users. While user-friendly options have been developed over the past decade for fast, streamlined data analysis, care must be taken in both processing the data and understanding any limitations, especially in the case of liquids. In this review, the same scattering data are analyzed using different total X-ray scattering software, in order to compare the accuracy of the extracted structure factors and associated pair distribution functions. The goal is to assess the best practices for extracting the most accurate liquid data for each software package. The importance of absolute normalization and the application of the most appropriate corrections are emphasized via quantitative comparisons between liquid sulfur and water. Additionally, an awareness of the competing conventions used to define the PDF in crystallography and liquids/glasses is crucial for both the downstream analyses of the data and a comparison with the previous results in the literature.
]]>Quantum Beam Science doi: 10.3390/qubs7020019
Authors: Constantine Kouderis Angelos G. Kalampounias
We have investigated the ultrasonically induced birefringence traces of aqueous solutions of dexamethasone disodium phosphate, a derivative of hydrocortisone (cortisol). The stationary birefringence and the transient built-up and decay relaxation processes were studied as a function of solution concentration, ultrasound frequency and intensity, as well as a function of temperature. The results were analyzed in view of structural peculiarities of the system in an effort to gain further insights into the molecular relaxation dynamics and the proposed self-association process occurring in the system. The detected ultrasonically induced birefringence relaxation is motivated by the rotational diffusion of dexamethasone disodium phosphate aggregates due to self-association depending on the solution concentration. The observed relaxation mechanism is directly linked to the hydrodynamic size of the acoustic field-induced self-assembly. The systematic analysis of the transient birefringence signals caused by the applied ultrasonic field allowed us to evaluate the interplay between permanent and induced dipoles with changing concentration, temperature, and ultrasound properties. The birefringence traces are adequately fitted with a stretched exponential law indicating the polydispersive nature of the self-aggregated molecular structures. The obtained results are described in the light of recent studies performed on this system.
]]>Quantum Beam Science doi: 10.3390/qubs7020018
Authors: Antonios Lionis Konstantinos Peppas Hector E. Nistazakis Andreas Tsigopoulos Keith Cohn Kyle R. Drexler
The Hellenic Naval Academy (HNA) reports the latest results from a medium-range, near-maritime, free-space laser-communications-testing facility, between the lighthouse of Psitalia Island and the academy’s laboratory building. The FSO link is established within the premises of Piraeus port, with a path length of 2958 m and an average altitude of 35 m, mainly above water. Recently, the facility was upgraded through the addition of a BLS450 scintillometer, which is co-located with the MRV TS5000/155 FSO system and a WS-2000 weather station. This paper presents the preliminary optical turbulence measurements, collected from 24 to 31 of May 2022, alongside the macroscopic meteorological parameters. Four machine-learning algorithms (random forest (RF), gradient boosting regressor (GBR), single layer (ANN), and deep neural network (DNN)) were utilized for refractive-index-structural-parameter regression modeling. Additionally, another DNN was used to classify the strength level of the optical turbulence, as either strong or weak. The results showed very good prediction accuracy for all the models. Specifically, the ANN algorithm resulted in an R-squared of 0.896 and a mean square error (MSE) of 0.0834; the RF algorithm also gave a highly acceptable R-squared of 0.865 and a root mean square error (RMSE) of 0.241. The Gradient Boosting Regressor (GBR) resulted in an R-squared of 0.851 and a RMSE of 0.252 and, finally, the DNN algorithm resulted in an R-squared of 0.79 and a RMSE of 0.088. The DNN-turbulence-strength-classification model exhibited a very acceptable classification performance, given the highly variability of our target value (Cn2), since we observed a predictive accuracy of 87% with the model.
]]>Quantum Beam Science doi: 10.3390/qubs7020017
Authors: Konstantin P. Savkin Efim M. Oks Alexey G. Nikolaev Georgy Yu. Yushkov
The interaction of ion beams with dielectric materials is an urgent problem, both from the point of view of practical application in ion implantation processes and for understanding the fundamental processes of charge compensation and the effective interaction of beam ions with a target surface. This paper presents the results of studies of the processes of compensation of the surface charge of an insulated collector upon interaction with a beam of metal ions with energies up to 50–150 keV. At low pressure (about 10−6 torr), removing the collector from the region of extraction and beam formation makes it possible to reduce the floating potential to a value of 5–10% of the total accelerating voltage. This phenomenon allows for the efficient implantation of metal ions onto the surface of alumina ceramics. We have shown that the sheet resistance of dielectric targets depends on the material of the implanted metal ions and decreases with an increase in the implantation dose by 3–4 orders of magnitude compared with the initial value at the level of 1012 Ω per square.
]]>Quantum Beam Science doi: 10.3390/qubs7020016
Authors: Yujiro Hayashi Daigo Setoyama Kunio Fukuda Katsuharu Okuda Naoki Katayama Hidehiko Kimura
Recently, nondestructive evaluation of the stresses localized in grains was achieved for plastically deformed low-carbon steel using scanning three-dimensional X-ray diffraction (S3DXRD) microscopy with a conical slit. However, applicable metals and alloys were restricted to a single phase and evaluated stress was underestimated due to the fixed Bragg angles of the conical slit optimized to αFe. We herein propose S3DXRD with a rotating spiral slit adaptable to various metals and alloys and accurate stress evaluation with sweeping Bragg angles. Validation experiments with a 50-keV X-ray microbeam were conducted for low-carbon steel as a body-centered cubic (BCC) phase and pure Cu as a face-centered cubic (FCC) phase. As a result of orientation mapping, polygonal grain shapes and clear grain boundaries were observed for both BCC and FCC metals. Thus, it was demonstrated that S3DXRD with a rotating spiral slit will be applicable to various metals and alloys, multiphase alloys, and accurate stress evaluation using a X-ray microbeam with a higher photon energy within an energy range determined by X-ray focusing optics. In principle, this implies that S3DXRD becomes applicable to larger and thicker metal and alloy samples instead of current miniature test or wire-shaped samples if a higher-energy X-ray microbeam is available.
]]>Quantum Beam Science doi: 10.3390/qubs7020015
Authors: Ayumu Yasue Mayu Kawakami Kensuke Kobayashi Junho Kim Yuji Miyazu Yuhei Nishio Tomohisa Mukai Satoshi Morooka Manabu Kanematsu
Neutron diffraction is a noncontact method that can measure the rebar strain inside concrete. In this method, rebar strain and stress are calculated using the diffraction profile of neutrons irradiated during a specific time period. In general, measurement accuracy improves with the length of the measurement time. However, in previous studies, the measurement time was determined empirically, which makes the accuracy and reliability of the measurement results unclear. In this study, the relationship between the measurement time and the measurement standard deviation was examined for reinforced concrete specimens under different conditions. The aim was to clarify the accuracy of the measurement of rebar stress using the neutron diffraction method. It was found that if the optical setup of the neutron diffractometer and the conditions of the specimen are the same, there is a unique relationship between the diffraction intensity and the rebar stress standard deviation. Furthermore, using this unique relationship, this paper proposes a method for determining the measurement time from the allowable accuracy of the rebar stress, which ensures the accuracy of the neutron diffraction method.
]]>Quantum Beam Science doi: 10.3390/qubs7020014
Authors: Yasuhiro Yamazaki Keisuke Shinomiya Tadaharu Okumura Kenji Suzuki Takahisa Shobu Yuiga Nakamura
The suspension plasma spray (SPS) method is expected to become a novel coating method because it can achieve various microstructures using a suspension with submicron spray particles. Thermal barrier coatings (TBCs) with a columnar structure, which might achieve high strain tolerance, can be obtained using the SPS technique. This study evaluated the internal stress distribution of the suspension-plasma-sprayed thermal barrier coating (SPS-TBC) with different columnar structures using hybrid measurement using high-energy synchrotron X-ray diffraction analysis and laboratory low-energy X-rays. The relationship between the microstructure and the internal stress distribution of the SPS-TBC was discussed on the basis of the experimental results. In addition, the in-plane internal stress was decreased by decreasing the column diameter. The thin columnar microstructure of the SPS-TBC has superior strain tolerance. The internal stresses in the SPS-TBC are periodic decrements caused by stress relaxation in porous layers in its column.
]]>Quantum Beam Science doi: 10.3390/qubs7020013
Authors: Jessica Brocchieri Elvira Scialla Antonio D’Onofrio Carlo Sabbarese
Diagnostic analyses on a contemporary painting on canvas were performed with X-ray fluorescence (XRF), multispectral imaging and scanning electron microscope/energy dispersive spectroscopy (SEM/EDS). The results of each method provided complementary information to deepen the knowledge of the pictorial technique. Multispectral imaging provided insight into the topmost layers. XRF analysis made it possible to characterize the chemical composition of some materials and pigments used by the artist. Additional information such as that relating to canvas preparation emerged with the SEM/EDS technique. The results reveal (i) the use of pre-treated industrial canvas; (ii) the preparatory layer consists of plaster covered with a primer with titanium white, zinc and lithopone; (iii) a layer of cadmium yellow ground was inserted to give depth and three-dimensionality to the painting; (iv) the absence of underlying design; (v) the characterized pigments are all contemporary and (vi) a fixative spray covers the paint.
]]>Quantum Beam Science doi: 10.3390/qubs7020012
Authors: Hiroshi Amekura Saif Ahmad Khan Pawan Kumar Kulriya Debdulal Kabiraj
Irradiation temperature (IT) dependence of the elongation efficiency of vanadium nanoparticles (NPs) in SiO2 was evaluated: The samples were irradiated with 120 MeV Ag9+ ions to a fluence of 1.0 × 1014 ions/cm2 each at ITs of 300, 433, 515, and 591 K, while the measurements were performed at room temperature. The vanadium was selected for the NP species because of the highest bulk m.p. of 1910 °C (2183 K) among all the species of the elemental metal NPs in which the shape elongation was observed. The highest m.p. could contribute negligible size changes of NPs against inevitable exposure to high temperatures for the IT dependence measurements. The elongation of V NPs was evaluated qualitatively by transmission electron microscopy (TEM) and quantitatively by optical linear dichroism (OLD) spectroscopy. The electron microscopy studies showed a pronounced elongation of NPs with ion irradiation at the elevated temperatures. The OLD signal was almost constant, or even slightly increased with increasing the IT from 300 to 591 K. This IT dependence provides a striking contrast to that of the ion hammering (IH) effect, which predicts a steep decrease with increasing IT. Combined with the other two counterevidence previously reported, the IH-related effect is excluded from the origin of the shape elongation of metal NPs in SiO2.
]]>Quantum Beam Science doi: 10.3390/qubs7020011
Authors: Andre Vatarescu
The presence of quantum Rayleigh scattering, or spontaneous emission, inside a dielectric medium such as a beam splitter or an interferometric filter prevents a single photon from propagating in a straight line. Modelling a beam splitter by means of a unitary transformation is physically meaningless because of the loss of photons. Additional missing elements from the conventional theory are the quantum Rayleigh-stimulated emission, which can form groups of photons of the same frequency, and the unavoidable parametric amplification of single photons in the original parame-tric crystal. An interference filter disturbs, through multiple internal reflections, the original stream of single photons, thereby confirming the existence of groups of photons being spread out to lengthen the coherence time. The approach of modelling individual, single measurements with probability amplitudes of a statistical ensemble leads to counterintuitive explanations of the experimental outcomes and should be replaced with pure states describing instantaneous measurements whose values are afterwards averaged.
]]>Quantum Beam Science doi: 10.3390/qubs7010010
Authors: Connor Kapahi Dusan Sarenac Markus Bleuel David G. Cory Benjamin Heacock Melissa E. Henderson Michael G. Huber Ivar Taminiau Dmitry Pushin
Neutrons are a powerful probe in material science with unique penetrating abilities. A major challenge stems from the fact that neutron optical devices are limited to refractive indices on the order of n≈1±10−5. By exploiting advances in precision manufacturing, we designed and constructed micro-meter period triangular grating with a high-aspect ratio of 14.3. The manufacturing quality is demonstrated with white-light interferometric data and microscope imaging. Neutron-scattering experiment results are presented, showing agreement with refraction modelling. The capabilities of neutron Fresnel prisms and lenses based on this design are contrasted with existing neutron focusing techniques, and the path separation of a prism-based neutron interferometer is estimated.
]]>Quantum Beam Science doi: 10.3390/qubs7010009
Authors: André Pimenta Valter Felix Matheus Oliveira Miguel Andrade Marcelo Oliveira Renato Freitas
In this work, four artworks dating from the 19th century by Brazilian painters Firmino Monteiro, Henrique Bernardelli, and Eliseu Visconti were analyzed by MA-XRF. Pb-L, Fe-K, and Hg-L were the main elemental maps obtained in all paintings. In the artworks of Henrique Bernardelli and Eliseu Visconti, maps of Cr-K and Co-K were also obtained. These results indicate that these Brazilian painters from the 19th century used few pigments to create their paintings, with the different hues coming mainly from ocher pigments. Using correlation image methods, no intentional mixtures of pigments made by the painters were found. These results indicate that the three painters used similar materials and techniques for preparing their pigments. These similarities are confirmed through statistical analysis by non-negative matrix factorization (NMF). In this method, it was possible to verify that the main bases of the contribution of the data registered in each artwork are the same. The analysis also revealed that one of Eliseu Visconti’s paintings had an underlying painting, and another artwork by Eliseu Visconti contained a golden pigment with Cu and Zn. These results have helped art historians and conservators understand the creation process of Brazilian artists in the 19th century.
]]>Quantum Beam Science doi: 10.3390/qubs7010008
Authors: Masayuki Nishida Stefanus Harjo Takuro Kawasaki Takayuki Yamashita Wu Gong
In this study, the thermal stress alterations generated in a tungsten fiber reinforced titanium composite (W/Ti composite) were evaluated by the neutron stress measurement method at cryogenic temperatures. The W/Ti composite thermal loads were repeated from room temperature to the cryogenic temperature (10 K), and alterations in thermal residual stress were evaluated using the neutron in situ stress measurement method. In this measurement, the stress alterations in the titanium matrix and the tungsten fibers were measured. This measurement was carried out by TAKUMI (MLF-BL19) of J-PARC, a neutron research facility in the Japan Atomic Agency. The measurement method of TAKUMI is the time-of-flight (TOF) method. Owing to this measurement method, the measurement time was significantly shortened compared to the angle-dispersion type measurement by a diffractometer. As a result of the measurement, large compressive stresses of about 1 GPa were generated in the tungsten fibers, and tensile stresses of about 100 MPa existed in the titanium matrix. The thermal stresses due to the temperature change between room temperature and cryogenic temperature is caused by the difference of thermal expansions between the tungsten fibers and the titanium matrix, and these stress values can be approximated by a simple elastic theory equation.
]]>Quantum Beam Science doi: 10.3390/qubs7010007
Authors: Jean-Marc Costantini Tatsuhiko Ogawa
The effects of electronic excitations on the ion sputtering of water ice are not well understood even though there is a clear dependence of the sputtering yield on the electronic stopping power of high-energy ions. Ion sputtering of amorphous water ice induced by electronic excitations is modelled by using the Coulomb explosion approach. The momentum transfer to ionized target atoms in the Coulomb field that is generated by swift ion irradiation is computed. Positively charged ions produced inside tracks are emitted from the surface whenever the kinetic energy gained in the repulsive electrical field is higher than the surface binding energy. For that, the energy loss of deep-lying ions to reach the surface is taken into account in the sputtering yield and emitted ion velocity distribution. Monte Carlo simulations are carried out by taking into account the interactions of primary ions and secondary electrons (δ-rays) with the amorphous water ice medium. A jet-like anisotropic ion emission is found in the perpendicular direction in the angular distribution of the sputtering yield for normal incidence of 1-MeV protons. This directional emission decreases with an increasing incidence angle and vanishes for grazing incidence, in agreement with experimental data on several oxides upon swift ion irradiation. The role of the target material’s properties in this process is discussed.
]]>Quantum Beam Science doi: 10.3390/qubs7010006
Authors: Dmitriy Beznosko Valeriy Aseykin Alexander Dyshkant Alexander Iakovlev Oleg Krivosheev Tatiana Krivosheev Valeriy Zhukov
The article describes the development, design, and upcoming construction and deployment of core modules of DUCK (Detector system of Unusual Cosmic-ray casKades), a cosmic-rays detector system aimed to verify and further study the latest advances in the cosmic-rays field and participate in the international collaborations searching for new types of events. The primary scientific goal for the DUCK project will be an independent verification of the detection of ‘unusual’ cosmic ray events by the Horizon-T detector system. A detailed study of events of this type is a vital step towards understanding the nature of cosmic rays, their origins, and details of interaction with the nuclei in the atmosphere. Further operations as part of the CREDO collaboration will contribute to the continued monitoring of the cosmic events. Additional intellectual value includes the design of the fast detection system with high timing resolution for cosmic events detection and the study of the temporal structure of extensive air showers that would also contribute to the current simulations. All the steps are conducted with student involvement and advance excellence in providing students with real research experience and competitive knowledge.
]]>Quantum Beam Science doi: 10.3390/qubs7010005
Authors: Iulian Otel
The present paper reviews the applications of Raman spectroscopy in dentistry in the past two decades. This technique is considered a highly promising optical modality, widely used for the chemical identification and characterization of molecular structures, providing detailed information on the structural arrangement, crystal orientations, phase, and polymorphism, molecular interactions and effects of bonding, chemical surrounding environment, and stress on samples. Raman spectroscopy has been appropriate to investigate both organic and inorganic components of dental tissues since it provides accurate and precise spectral information on present minerals through the observation of the characteristic energies of their vibrational modes. This method is becoming progressively important in biomedical research, especially for non-invasiveness, non-destructiveness, high biochemical specificity, low water sensitivity, simplicity in analyzing spectral parameters, near-infrared region capability, and in vivo remote potential by means of fiber-optics. This paper will address the application of Raman spectroscopy in different fields of dentistry, found to be the most relevant and prevalent: early recognition of carious lesions; bleaching products performance; demineralizing effect from low-pH foods and acidic beverages; and efficiency of remineralization agents. Additionally, this review includes information on fiber-optic remote probe measurements. All described studies concern caries detection, enamel characterization, and assessment indicating how and to what extent Raman spectroscopy can be applied as a complementary diagnostic method.
]]>Quantum Beam Science doi: 10.3390/qubs7010004
Authors: Satoshi Koizumi Yohei Noda Takumi Inada Tomoki Maeda Shiho Yada Tomokazu Yoshimura Hiroshi Shimosegawa Hiroya Fujita Munehiro Yamada Yukako Matsue
A novel surfactant of N–dodecanoyl–N–(2-hydroxyethyl)–β–alanine (coded as C12–EtOH–βAla) was synthesized by modifying the methyl group of N–dodecanoyl–N–methyl–β–alanine (coded as C12–Me–βAla). Amino-acid-type surfactants (C12–EtOH–βAla and C12–Me–βAla) are more healthy and environmentally friendly compared to sodium dodecyl sulfate (SDS). To investigate the microstructures of these new surfactants, we employed a method of time-of-flight small-angle neutron scattering (TOF SANS) at a pulsed neutron source, Tokai Japan (J–PARC). The advances in TOF SANS enable simultaneous multiscale observations without changing the detector positions, which is usually necessary for SANS at the reactor or small-angle X-ray scattering. We performed in situ and real-time observations of microstructures of collapsing shampoo foam covering over a wide range of length scales from 100 to 0.1 nm. After starting an air pump, we obtained time-resolved SANS from smaller wave number, small-angle scattering attributed to (1) a single bimolecular layer with a disk shape, (2) micelles in a bimolecular layer, and (3) incoherent scattering due to the hydrogen atoms of surfactants. The micelle in the foam film was the same size as the micelle found in the solution before foaming. The film thickness (~27 nm) was stable for a long time (<3600 s), and we simultaneously found a Newton black film of 6 nm thickness at a long time limit (~1000 s). The incoherent scattering obtained with different contrasts using protonated and deuterated water was crucial to determining the water content in the foam film, which was about 10~5 wt%.
]]>Quantum Beam Science doi: 10.3390/qubs7010003
Authors: Alessio Parisi Chris J. Beltran Keith M. Furutani
The computation of the relative biological effectiveness (RBE) is a fundamental step in the planning of cancer radiotherapy treatments with accelerated ions. Numerical parameters derived analyzing the dose response of the chosen cell line after irradiation to photons (i.e., α and β, namely the linear and quadratic terms of the linear-quadratic model of cell survival) are generally used as input to biophysical models to predict the ion RBE. The α/β ratio for the photon exposure is generally regarded as an indicator of cell radiosensitivity. However, previous studies suggest that α/β might not be a sufficient parameter to model the RBE of relatively high linear energy transfer (LET) radiation such as carbon ions. For a fixed α/β, the effect of the absolute values of α and β on the computed RBE is underexplored. Furthermore, since α and β are anticorrelated during the fit of the photon-exposed in vitro survival data, different linear-quadratic fits could produce different sets of α and β, thus affecting the RBE calculations. This article reports the combined effect of the α/β ratio and the absolute values α and β on the RBE computed with the Mayo Clinic Florida microdosimetric kinetic model (MCF MKM) for 12C ions of different LET. Furthermore, we introduce a theory-based strategy to potentially mitigate the anticorrelation between α and β during the fit of the photon dose-response biological data.
]]>Quantum Beam Science doi: 10.3390/qubs7010002
Authors: Quantum Beam Science Editorial Office Quantum Beam Science Editorial Office
High-quality academic publishing is built on rigorous peer review [...]
]]>Quantum Beam Science doi: 10.3390/qubs7010001
Authors: Masao Watanabe Takumi Kihara Hiroyuki Nojiri
A pulsed magnet system has been developed as a new user-friendly sample environment equipment at the Materials and Life Science Experimental Facility in Japan Proton Accelerator Research Complex. It comprises a vacuum chamber, a 4 K closed-cycle refrigerator for samples, and a nitrogen bath made of a stainless-steel tube with a miniature solenoidal coil. The coil is cooled by liquid nitrogen supplied by an automatic liquid nitrogen supply system, and the sample is cooled by a refrigerator. This combination facilitates the automatic high magnetic field diffraction measurement for the user’s operation. A relatively large scattering angle 2θ is up to 42°, which is significantly wider than the previous setup. Neutron diffraction experiments were performed on a multiferroic TbMnO3 and the field dependence of the diffraction peaks was clearly observed. The new pulsed magnet system was established for a practical high magnetic field diffraction for the user program.
]]>Quantum Beam Science doi: 10.3390/qubs6040033
Authors: Monia Vadrucci
Precious cultural heritage has been inherited through past activities and maintained by the generations, and it includes artifacts and objects preserved in institutes or museum areas. As part of the study, the conservation of art objects and other cultural assets was carried out at the ENEA Frascati Research Center and attention was paid to the biodegradation aspect caused by microorganisms that cause the loss of information and artistic characteristics contained in the artifacts, for example, through covering them, the loss of color and the smearing of decorative or writing strokes. A non-chemical and non-toxic, completely ecological approach is used as an alternative bio-removal treatment to control the pathogens: these are the disinfection procedures that were applied using the REX machine. The beams of photons and electrons produced by this facility carried out anti-biodegradation activities for the control of deteriogens isolated from multi-material works. This communication concerns the REX machine, which is framed in the context of ENEA and in the panorama of activities carried out for the conservation of cultural heritage, presenting its application to case studies in which the developed technique was demonstrated as a non-invasive treatment for bio-degradation removal.
]]>Quantum Beam Science doi: 10.3390/qubs6040032
Authors: Andre Vatarescu
Controllable, quantum-strong correlations of polarization states can be implemented with multi-photon independent states. Polarization-based photonic quantum correlations can be traced back to the overlap of the polarization Stokes vectors on the Poincaré sphere between two polarization filters. The quantum Rayleigh scattering prevents a single photon from propagating in a straight line inside a dielectric medium, and it also provides a mechanism for the projective measurement of polarization. Complexities associated with single-photon sources and detectors can be eliminated because the quantum Rayleigh scattering in a dielectric medium destroys entangled photons. Entanglement-free, identical sources and processing devices give rise to correlations rather than these being caused by “quantum nonlocality”. These analytic developments were prompted by the vanishing expectation values of the Pauli spin vector for a single photon of maximally entangled photonic Bell states.
]]>Quantum Beam Science doi: 10.3390/qubs6040031
Authors: Chris J. Benmore Angela Edwards Oliver L. G. Alderman Brian R. Cherry Pamela Smith Daniel Smith Stephen Byrn Richard Weber Jeffery L. Yarger
To enhance the solubility of orally administered pharmaceuticals, liquid capsules or amorphous tablets are often preferred over crystalline drug products. However, little is known regarding the variation in bonding mechanisms between pharmaceutical molecules in their different disordered forms. In this study, liquid and melt-quenched glassy carbamazepine have been studied using high energy X-ray diffraction and modeled using Empirical Potential Structure Refinement. The results show significant structural differences between the liquid and glassy states. The liquid shows a wide range of structures; from isolated molecules, to aromatic ring correlations and NH-O hydrogen bonding. Upon quenching from the liquid to the glass the number of hydrogen bonds per molecule increases by ~50% at the expense of a ~30% decrease in the close contact (non-bonded) carbon-carbon interactions between aromatic rings. During the cooling process, there is an increase in both singly and doubly hydrogen-bonded adjacent molecules. Although hydrogen-bonded dimers found in the crystalline states persist in the glassy state, the absence of a crystalline lattice also allows small, hydrogen-bonded NH-O trimers and tetramers to form. This proposed model for the structure of glassy carbamazepine is consistent with the results from vibrational spectroscopy and nuclear magnetic resonance.
]]>Quantum Beam Science doi: 10.3390/qubs6040030
Authors: Francesco Schillaci Lorenzo Giuffrida Maksym Tryus Filip Grepl Stanislav Stancek Andriy Velyhan Valeriia Istokskaia Tadzio Levato Giada Petringa Giuseppe Cirrone Josef Cupal Lucia Koubiková Davorin Peceli Jeffrey Jarboe Tarcio de Castro Silva Martin Cuhra Timofej Chagovets Vasiliki Kantarelou Marco Tosca Vahagn Ivanyan Martina Greplová Žáková Jan Psikal Roman Truneček Anna Cimmino Roberto Versaci Veronika Olšovlcová Daniel Kramer Pavel Bakule Jan Ridky Georg Korn Bedrich Rus Daniele Margarone
We report on the technological commissioning of the Laser–Plasma Ion Accelerator section of the ELIMAIA user beamline at the ELI Beamlines facility in the Czech Republic. The high-peak, high-average power L3-HAPLS laser system was used with an energy of ~10 J and pulse duration of ~30 fs on target, both in single-pulse and high repetition-rate (~0.5 Hz) mode. The laser pulse was tightly focused to reach ultrahigh intensity on target (~1021 W/cm2) and sustain such laser–plasma interaction regime during high repetition-rate operations. The laser beam, ion beam, and laser–plasma emission were monitored on a shot-to-shot basis, and online data analysis at 0.5 Hz was demonstrated through the full set of used diagnostics (e.g., far and near field, laser temporal diagnostics, X- and gamma-ray detectors, Thomson Parabola ion spectrometer, time-of-flight ion detectors, plasma imaging, etc.). The capability and reliability of the ELIMAIA Ion Accelerator was successfully demonstrated at a repetition rate of 0.5 Hz for several hundreds of consecutive laser shots.
]]>Quantum Beam Science doi: 10.3390/qubs6040029
Authors: Andre Vatarescu
Three physical elements are missing from the conventional formalism of quantum photonics: (1) the quantum Rayleigh spontaneous and stimulated emissions; (2) the unavoidable parametric amplification; and (3) the mixed time-frequency spectral structure of a photonic field which specifies its duration or spatial extent. As a single photon enters a dielectric medium, the quantum Rayleigh scattering prevents it from propagating in a straight-line, thereby destroying any possible entanglement. A pure dynamic and coherent state composed of two consecutive number states, delivers the correct expectation values for the number of photons carried by a photonic wave front, its complex optical field, and phase quadratures. The intrinsic longitudinal and lateral field profiles associated with a group of photons for any instantaneous number of photons are independent of the source. These photonic properties enable a step-by-step analysis of the correlation functions characterizing counting of coincident numbers of photons or intensities with unity visibility interference, spanning the classical and quantum optic regimes.
]]>Quantum Beam Science doi: 10.3390/qubs6040028
Authors: Akihiko Hirata
To analyze amorphous structure models obtained by a molecular dynamics (or reverse Monte Carlo) simulation, we propose a virtual angstrom-beam electron diffraction analysis. In this analysis, local electron diffraction patterns are calculated for the amorphous models at equal intervals as performed in the experiment, and the local structures that generate paired diffraction spots in the diffraction patterns are further analyzed by combining them with a Fourier transform and a Voronoi polyhedral analysis. For an example of Zr80Pt20, an aggregate of coordination polyhedra is formed which generates similar diffraction patterns from most parts within the aggregate. Furthermore, the coordination polyhedra are connected in certain orientational relationships which could enhance the intensity of the diffraction spots.
]]>Quantum Beam Science doi: 10.3390/qubs6030027
Authors: Cheng-Yan Guo Tzu-Lu Lin Tung-Li Hsieh
Since the nuclear energy leakage that occurred at the Fukushima nuclear power plant in Japan, people have paid more attention to the danger of environmental radiation. Environmental radiation is monitored using Geiger counters, which are not easy to obtain in some areas. Therefore, this research proposes an open-source and low-cost handheld Geiger counter that uses solar energy to charge lithium-ion batteries. Our design can provide a low-cost environmental radiation monitoring platform and effectively enhance the public’s scientific education awareness of radiation hazards. The measured dose rate can be output through the serial port, allowing a LoRa wireless network to transmit data to a database. When the sensing network deployed by the radiometer detects that the radiation value of the area is abnormally increased, it can issue an alarm to the government for the first time. Moreover, the low-power radiometer design can reduce energy consumption, reduce the burden on the ecological environment caused by the deployment of the sensing network, and provide sustainability for the environment.
]]>Quantum Beam Science doi: 10.3390/qubs6030026
Authors: Johanna K. Jochum Jos F. K. Cooper Lukas M. Vogl Peter Link Olaf Soltwedel Peter Böni Christian Pfleiderer Christian Franz
MIEZE (Modulation of IntEnsity with Zero Effort) spectroscopy is a high-resolution spin echo technique optimized for the study of magnetic samples and samples under depolarizing conditions. It requires a polarization analyzer in between spin flippers and the sample position. For this, the device needs to be compact and insensitive to stray fields from large magnetic fields at the sample position. For MIEZE, in small angle scattering geometry, it is further essential that the analyzer does not affect the beam profile, divergence, or trajectory. Here, we compare different polarization analyzers for MIEZE and show the performance of the final design, a transmission bender, which we compare to McStas simulations. Commissioning experiments have uncovered spurious scattering in the scattering profile of the bender, which most likely originates from double Bragg scattering in bent silicon.
]]>Quantum Beam Science doi: 10.3390/qubs6030025
Authors: Taisen Zuo Zhanjiang Lu Changdong Deng Songwen Xiao Yongcheng He Zhenqiang He Xiong Lin Changli Ma Zehua Han He Cheng
A compact nested rotate sextupole permanent magnet (Nest-Rot-SPM) lens was designed for the focusing of pulsed neutrons. It is based on the working conditions of the Very Small Angle Neutron Scattering (VSANS) instrument at the China Spallation Neutron Source (CSNS), and is expected to focus a neutron pulse from 6 Å to 10.5 Å, without chromatic aberration. Three hurdles must be addressed, i.e., the tremendous torque, the heat deposition, and the synchronization with the neutron pulse, respectively. The bore diameter and segment length of the lens are optimized using a formula analysis of the key parameters and model simulations of the torque and heat deposition. A twin torque canceling design is used to reduce the torque to one-third of its original value, or even lower. The goal of this project is to take the device into practical use in the VSANS at the CSNS.
]]>Quantum Beam Science doi: 10.3390/qubs6030024
Authors: Pasang Lin Misiolek Wei Masuno Tsukamoto Hori Sato Tao Yudhistiro Yunus
The need for thin foil welding is increasing significantly, particularly in the electronic industries. The technologies that are currently available limit the joining processes in terms of materials and their geometries. In this paper, a series of trials of fusion welding (bead-on- plate) of commercially pure titanium (CPTi) foils were conducted using a blue diode laser (BDL) welding method. The power used was 50 W and 100 W for 0.1 mm and 0.2 mm thick foils, respectively. Following welding, various samples were prepared to examine the weld profiles, microstructures, hardness, tensile strength, and fracture surface characteristics. The results showed that the base metal (BM) had an annealed microstructure with equiaxed grains, while the weld zones contained martensite (α’) with large grains. The hardness increased in both regions, from around 123 HV to around 250 HV, in the heat-affected zone (HAZ) and fusion zone (FZ) areas. The tensile tests revealed that the strengths of the welded samples were slightly lower than the unwelded samples, i.e., UTS = 300–350 MPa compared with 325–390 MPa for the unwelded samples. Fracture took place within the BM area. All of the samples, welded and unwelded, showed identical fracture mechanisms, i.e., microvoid coalescence or ductile fracture. The weld zone experienced very small strains (elongation) at fracture, which indicates a good weld quality.
]]>Quantum Beam Science doi: 10.3390/qubs6030023
Authors: Vadim Parfenov Alexander Galushkin Tatiana Tkachenko Vladimir Aseev
The purpose of this work is the study of laser cleaning of historical paper. The effect of laser exposure of the paper reflectance, fracture resistance and acidity was investigated. The paper surface roughness before and after laser treatment was analyzed by optical and scanning electron microscopy. It was shown that use of multi-pulse micromachining in combination with high-speed scanning of laser beams provides high safety for paper cleaning. The optimal parameters of laser radiation for effective and safe cleaning are a power density of about 2 × 105 W/cm2 at a wavelength of 1.06 μm, pulse repetition rate is 20 kHz; and a beam scanning speed of 200 mm/s–500 mm/s. The selective laser cleaning method for books and documents was proposed. Selective cleaning is achieved by means of high-precision control of the trajectory of movement of laser beams.
]]>Quantum Beam Science doi: 10.3390/qubs6020022
Authors: Hidekazu Takano Yanlin Wu Tetsuo Samoto Atsushi Taketani Takaoki Takanashi Chihiro Iwamoto Yoshie Otake Atsushi Momose
Neutron imaging based on a compact Talbot–Lau interferometer was demonstrated using the RIKEN accelerator-driven compact neutron source (RANS). A compact Talbot–Lau interferometer consisting of gadolinium absorption gratings and a silicon phase grating was constructed and connected to the RANS. Because of pulsed thermal neutrons from the RANS and a position-sensitive detector equipped with time-of-flight (TOF) analysis, moiré interference patterns generated using the interferometer were extracted at a TOF range around the design wavelength (2.37 Å) optimal for the interferometer. Differential phase and scattering images of the metal rod samples were obtained through phase-stepping measurements with the interferometer. This demonstrates the feasibility of neutron phase imaging using a compact neutron facility and the potential for flexible and unique applications for nondestructive evaluation.
]]>Quantum Beam Science doi: 10.3390/qubs6020021
Authors: Akihiro Iwase Yuichi Saitoh Atsuya Chiba Fuminobu Hori Norito Ishikawa
C-axis-oriented EuBa2Cu3O7−x oxide films that were 100 nm thick were irradiated with 0.5 MeV C monoatomic ions, 2 MeV C4 cluster ions and 4 MeV C8 cluster ions at room temperature. Before and after the irradiation, X-ray diffraction (XRD) measurement was performed using Cu-Ka X-ray. The c-axis lattice constant increased almost linearly as a function of numbers of irradiating carbon ions, but it rarely depended on the cluster size. Cluster size effects were observed in the XRD peak intensity and the XRD peak width. With increasing the cluster size, the decrease in peak intensity becomes more remarkable and the peak width increases. The experimental result implies that the cluster ions with a larger size provide a more localized energy deposition in a sample, and cause larger and more inhomogeneous lattice disordering. As such, local and large lattice disordering acts as a pinning center for quantum vortex; energetic carbon-cluster ion irradiation will be effective for the increment in the critical current of EuBa2Cu3O7−x superconductors.
]]>Quantum Beam Science doi: 10.3390/qubs6020020
Authors: Jorge E. Fernandez Francesco Teodori
The emission of characteristic lines after X-ray excitation is usually explained as the consequence of two independent and consecutive physical processes: the photoelectric ionization produced by incoming photons and the successive spontaneous atomic relaxation. However, the photoelectric effect is not the only ionization mechanism driven by incoming photons. It has been recently shown that Compton ionization is another possible process that contributes not negligibly to the ionization of the L and M shells. In addition, the secondary electrons from these two interactions, photoelectric and Compton, are also able to ionize the atom by means of so-called impact ionization. Such a contribution has been recently described, showing that it can be relevant in cases of monochromatic excitation for certain lines and elements. A third mechanism of line modification is the so-called self-enhancement produced by absorption of the tail of Lorentzian distribution of the characteristic line, which mainly modifies the shape of the lines but also produces an intensity increase. The four effects contribute to the formation of the characteristic line and must be considered to obtain a precise picture in terms of the shell and the element. This work furnishes a review of these contributions and their formal theoretical descriptions. It gives a complete picture of the photon kernel, describing the emission of characteristic X-rays comprising the main photoelectric contribution and the three effects of lower extent. All four contributions to the characteristic X-ray line must be followed along successive photon interactions to describe multiple scattering using the Boltzmann transport equation for photons.
]]>Quantum Beam Science doi: 10.3390/qubs6020019
Authors: Ahmad Aminzadeh Sasan Sattarpanah Karganroudi Mohammad Saleh Meiabadi Dhanesh G. Mohan Kadiata Ba
The benefits of laser welding include higher production values, deeper penetration, higher welding speeds, adaptability, and higher power density. These characteristics make laser welding a superior process. Many industries are aware of the benefits of switching to lasers. For example, metal-joining is migrating to modern industrial laser technology due to improved yields, design flexibility, and energy efficiency. However, for an industrial process to be optimized for intelligent manufacturing in the era of Industry 4.0, it must be captured online using high-quality data. Laser welding of aluminum alloys presents a daunting challenge, mainly because aluminum is a less reliable material for welding than other commercial metals such as steel, primarily because of its physical properties: high thermal conductivity, high reflectivity, and low viscosity. The welding plates were fixed by a special welding fixture, to validate alignments and improve measurement accuracy, and a Computer-Aided Inspection (CAI) using 3D scanning was adopted. Certain literature has suggested real-time monitoring of intelligent techniques as a solution to the critical problems associated with aluminum laser welding. Real-time monitoring technologies are essential to improving welding efficiency and guaranteeing product quality. This paper critically reviews the research findings and advances for real-time monitoring of laser welding during the last 10 years. In the present work, a specific methodology originating from process monitoring using Computer-Aided Inspection in laser-welded blanks is reviewed as a candidate technology for a digital twin. Moreover, a novel digital model based on CAI and cloud manufacturing is proposed.
]]>Quantum Beam Science doi: 10.3390/qubs6020018
Authors: Jaroslav Jánský Jiří Janda Michal Košťál Zdeněk Matěj Tomáš Bílý Věra Mazánková Filip Mravec František Cvachovec
Liquid organic scintillators are important devices for measurements of neutron radiation. Currently, large-scale liquid organic scintillators have capabilities of detecting neutrons, but the determination of the neutron energy spectra is a challenge. This work aims to measure the responses of two liquid two-component scintillators to mono-energetic neutron radiation and to determine their light output function, which is necessary for proper neutron energy spectra determination. Both scintillators are composed of the solvent di-iso-propyl-naphthalene (DIPN) mixed isomers. The first scintillator, labeled PYR5/DIPN, contains the luminophore 1-phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline with a concentration of 5 g/L. The second scintillator labeled THIO5/DIPN contains the luminophore 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene also with a concentration of 5 g/L. The responses to neutron energies of 1.5 MeV, 2.5 MeV, and 19 MeV are measured at PTB in Braunschweig. The responses to neutron energies of 2.45 MeV and 14 MeV were measured at CTU in Prague using DD and DT reactions. The responses to a silicon filtered beam were measured at Research Centre Řež. The measurements were processed using a two-parameter spectrometric system NGA-01 to discriminate neutrons from gamma rays. The obtained responses are dominated by recoil protons from elastic collisions of neutrons with hydrogen atoms. The edge of the response of recoil protons gives information about the light output of neutrons, compared to gamma rays for the same radiation energy. The light output function for protons in the PYR5/DIPN scintillator is L(Ep)=0.6294Ep−1.00(1−exp(−0.4933Ep0.95)). The light output function for protons in the THIO5/DIPN scintillator is L(Ep)=0.6323Ep−1.00(1−exp(−0.4986Ep0.9883)). The light output functions well resemble the standard shape, and they are quite similar to each other. That suggests a weak influence of the luminophore on the light output function. The light output functions are ready to be incorporated to the response matrix for the neutron energy spectra determination.
]]>Quantum Beam Science doi: 10.3390/qubs6020017
Authors: Chiara Confalonieri Riccardo Casati Elisabetta Gariboldi
Al-Sn binary system is a miscibility gap alloy consisting of an Al-rich phase and a Sn-rich phase. This system is traditionally applied in bearings and more recently found application as form-stable phase change material (PCM) exploiting solid-liquid phase transition of Sn. A careful choice of production process is required to avoid macro-segregation of the two phases, which have different densities and melting temperatures. In the present study, the additive manufacturing process known as laser powder bed fusion (LPBF) was applied to an Al-Sn alloy with 20% volume of Sn, as a rapid solidification process. The effect of process parameters on microstructure and hardness was evaluated. Moreover, feasibility and stability with thermal cycles of a lattice structure of the same alloy were experimentally investigated. An Al-Sn lattice structure could be used as container for a lower melting organic PCM (e.g., a paraffin or a fatty acid), providing high thermal diffusivity thanks to the metallic network and a “safety system” reducing thermal diffusivity if the system temperature overcomes Sn melting temperature. Even if focused on Al-Sn to be applied in thermal management systems, the study offers a contribution in view of the optimization of manufacturing processes locally involving high solidification rates and reheat cycles in other miscibility gap alloys (e.g., Fe-Cu) with similar thermal or structural applications.
]]>Quantum Beam Science doi: 10.3390/qubs6020016
Authors: Suprakash C. Roy
India holds a respectable position globally in X-ray research, particularly in X-ray crystallography. X-ray research in India is as old as the discovery of X-rays and the history of X-ray research in colonial India is fascinating. The purpose of this paper is to present how India participated in X-ray research and how X-ray research initiated by C.V. Raman, the only Indian Nobel Laureate in physics, at the Indian Association for the Cultivation of Science (IACS) paved the way to proliferate X-ray research in all parts of India and acted as the foundation stone of modern X-ray research in India. With limited resources under the British rule (India became independent in 1947), readers will find that the research work performed by Indians is commendable. This article is neither comprehensive nor detailed but will give the readers a flavour of the high-quality X-ray research that was performed in India in the early years after the discovery of X-rays.
]]>Quantum Beam Science doi: 10.3390/qubs6020015
Authors: Zubair H. Tarif Adebiyi Oresegun Auwal Abubakar Azmi Basaif Hafiz M. Zin Kan Yeep Choo Siti A. Ibrahim Hairul Azhar Abdul-Rashid David A. Bradley
The quality of treatment delivery as prescribed in radiotherapy is exceptionally important. One element that helps provide quality assurance is the ability to carry out time-resolved radiotherapy dose measurements. Reports on doped silica optical fibers scintillators using radioluminescence (RL) based radiotherapy dosimetry have indicated merits, especially regarding robustness, versatility, wide dynamic range, and high spatial resolution. Topping the list is the ability to provide time-resolved measurements, alluding to pulse-by-pulse dosimetry. For effective time-resolved dose measurements, high temporal resolution is enabled by high-speed electronics and scintillator material offering sufficiently fast rise and decay time. In the present work, we examine the influence of Ge doping on the RL response of Ge-doped silica optical fiber scintillators. We particularly look at the size of the Ge-doped core relative to the fiber diameter, and its associated effects as it is adjusted from single-mode fiber geometry to a large core-to-cladding ratio structure. The primary objective is to produce a structure that facilitates short decay times with a sufficiently large yield for time-resolved dosimetry. RL characterization was carried out using a high-energy clinical X-ray beam (6 MV), delivered by an Elekta Synergy linear accelerator located at the Advanced Medical and Dental Institute, Universiti Sains Malaysia (USM). The Ge-doped silica optical fiber scintillator samples, fabricated using chemical vapor deposition methods, comprised of large core and small core optical fiber scintillators with high and low core-to-cladding ratios, respectively. Accordingly, these samples having different Ge-dopant contents offer distinct numbers of defects in the amorphous silica network. Responses were recorded for six dose-rates (between 35 MU/min and 590 MU/min), using a photomultiplier tube setup with the photon-counting circuit capable of gating time as small as 1 μs. The samples showed linear RL response, with differing memory and afterglow effects depending on its geometry. Samples with a large core-to-cladding ratio showed a relatively short decay time (<1 ms). The results suggest a contribution of Ge-doping in affecting the triplet states of the SiO2 matrix, thereby reducing phosphorescence effects. This is a desirable feature of scintillating glass materials that enables avoiding the pulse pile-up effect, especially in high dose-rate applications. These results demonstrate the potential of Ge-doped optical-fiber scintillators, with a large core-to-cladding ratio for use in time-resolved radiation dosimetry.
]]>Quantum Beam Science doi: 10.3390/qubs6020014
Authors: William Chuirazzi Aaron Craft Burkhard Schillinger Jesus Mendoza Steven Cool Adrian Losko
Fast neutrons enable a nondestructive examination of dense, large, and highly attenuating samples due to their lower interaction probability compared to thermal neutrons. However, this also creates a challenge in fast neutron imaging, as the thicker sensors necessary to detect fast neutrons degrade an image’s spatial resolution due to scattering within the sensor and the indeterminate depth of interaction in the sensor. This work explores the advantages of a fast neutron imaging screen with a layered polymer-phosphor screen approach as opposed to a mixed polymer-phosphor screen typically used in fast neutron imaging. Proton recoil is the primary conversion mechanism for fast neutron imaging. Simulations showed that the recoil proton range of typical fast neutrons is approximately 200 µm, however, tests at Idaho National Laboratory revealed that the light output of these screens increased at much greater polymer thicknesses. The NECTAR fast neutron beamline at FRM II was used to test the imaging performance of layered fast neutron imaging screens. Distinguishing between the fast-neutron and γ-ray signals is a major challenge in fast neutron imaging because all fast neutron sources also produce γ-rays. A relative comparison between a control plate and the fast neutron screen was made to distinguish between a γ-ray and fast neutron signals. MCNP modeling quantified the γ-ray and fast neutron contributions to the images measured at NECTAR, which were approximately a 75% γ-ray image.
]]>Quantum Beam Science doi: 10.3390/qubs6010013
Authors: Thomas Schenkel Walid Redjem Arun Persaud Wei Liu Peter A. Seidl Ariel J. Amsellem Boubacar Kanté Qing Ji
Short-pulse ion beams have been developed in recent years and now enable applications in materials science. A tunable flux of selected ions delivered in pulses of a few nanoseconds can affect the balance of defect formation and dynamic annealing in materials. We report results from color center formation in silicon with pulses of 900 keV protons. G-centers in silicon are near-infrared photon emitters with emerging applications as single-photon sources and for spin-photon qubit integration. G-centers consist of a pair of substitutional carbon atoms and one silicon interstitial atom and are often formed by carbon ion implantation and thermal annealing. Here, we report on G-center formation with proton pulses in silicon samples that already contained carbon, without carbon ion implantation or thermal annealing. The number of G-centers formed per proton increased when we increased the pulse intensity from 6.9 × 109 to 7.9 × 1010 protons/cm2/pulse, demonstrating a flux effect on G-center formation efficiency. We observe a G-center ensemble linewidth of 0.1 nm (full width half maximum), narrower than previously reported. Pulsed ion beams can extend the parameter range available for fundamental studies of radiation-induced defects and the formation of color centers for spin-photon qubit applications.
]]>Quantum Beam Science doi: 10.3390/qubs6010012
Authors: Kazumasa Narumi Hiroshi Naramoto Keisuke Yamada Atsuya Chiba Yuichi Saitoh
Sputtering yields of Si have been measured for C60 ions in the energy range from 10 to 540 keV, where the nuclear stopping is dominant, by measuring thickness change of a pre-amorphized layer with conventional Rutherford-backscattering spectroscopy. The measured sputtering yield shows the maximum, which is approximately 600 Si/C60, around 100 keV. Comparing with the sputtering yields for a monatomic ion calculated both based on the linear-collision-cascade theory of Sigmund and using the SRIM2008 code, nonlinear effect on the sputtering yield has been observed. The nonlinear effect depends on the energy of C60 ions: it is very large around the energies where the sputtering yield has the maximum and hardly observed at 10 keV.
]]>Quantum Beam Science doi: 10.3390/qubs6010011
Authors: Vadim Parfenov Sergei Igoshin Dmitriy Masaylo Alexey Orlov Dzmitry Kuliashou
Three-dimensional laser scanning is a novel measurement technique that is frequently used for the documentation of cultural heritage (CH) objects. In the process of 3D scanning, one can obtain computing 3D models of artworks to be documented. It allows one to produce detailed digitized archives of important CH objects. Moreover, the use of 3D scanning enables the digital reconstruction of architectural fragments, sculptures, and other artworks. One more important application of this technique relates to the creation of molds and replicas for replacements of outdoor CH objects in case their preservation requirements do not allow them to remain in their original place due to the influence of environmental factors. One of the most effective ways of creating replicas is the use of laser additive technologies. Therefore, the combination of 3D scanning and additive technologies is a very promising way of preservation of CH. This paper describes several case studies concerned with the combined usage of 3D laser scanning and additive technologies for digital reconstruction and replication and of outdoor sculptures in St. Petersburg city. One of them is the reconstruction of the zinc sculpture “Eva at the fountain” (XIX century, England), which was destroyed during WWII. Its replica was created by means of laser stereolithography. Eventually, one more project is related to the reconstruction of the fragment of the sufficiently damaged cast-iron XIX century monument. This object was reconstructed using two laser technologies: direct metal laser sintering (DMLS), and laser cladding (LC).
]]>Quantum Beam Science doi: 10.3390/qubs6010010
Authors: Alberto Torralba Lidia Palenciano Alicia Reija Juan Rigla Juan Peñas Juan Llerena Ramiro Contreras-Martínez José Benlliure Ana Vega Miguel Aguado-Barrera Camilo Ruiz Michael Seimetz
Laser–plasma proton sources and their applications to preclinical research has become a very active field of research in recent years. In addition to their small dimensions as compared to classical ion accelerators, they offer the possibility to study the biological effects of ultra-short particle bunches and the correspondingly high dose rates. We report on the design of an experimental setup for the irradiation of cell cultures at the L2A2 laboratory at the University of Santiago de Compostela, making use of a 1.2 J Ti: Sapphire laser with a 10 Hz repetition rate. Our setup comprises a proton energy separator consisting of two antiparallel magnetic fields realized by a set of permanent magnets. It allows for selecting a narrow energy window around an adaptable design value of 5 MeV out of the initially broad spectrum typical for Target Normal Sheath Acceleration (TNSA). At the same time, unwanted electrons and X-rays are segregated from the protons. This part of the setup is located inside the target vessel of the L2A2 laser. A subsequent vacuum flange sealed with a thin kapton window allows for particle passage to external sample irradiation. A combination of passive detector materials and real-time monitors is applied for measurement of the deposited radiation dose. A critical point of this interdisciplinary project is the manipulation of biological samples under well-controlled, sterile conditions. Cell cultures are prepared in sealed flasks with an ultra-thin entrance window and analysed at the nearby Fundación Pública Galega Medicina Xenómica and IDIS. The first trials will be centred at the quantification of DNA double-strand breaks as a function of radiation dose.
]]>Quantum Beam Science doi: 10.3390/qubs6010009
Authors: Iuliia Ruzankina Vadim Parfenov Oleg Vasiliev Oleg Zotov Alexandra Zotova
This article is devoted to the study of the possibility of the passivation of iron-based metallic materials. The experimental results obtained for the laser treatment of carbon steel model samples by the radiation of repetitively pulsed and continuous-wave 1.064 µm Nd:YAG lasers are described. It is shown that the laser treatment allows the formation of dense protection films, 62–77 microns thick, on the steel surface. The films enhance the anticorrosion properties of the metal. Exposure to laser radiation reduces the surface roughness (from Ra = 0.53 µm to Ra = 0.38 µm). Laser radiation power densities of 10.2 × 105 W/cm2 and 10.7 × 105 W/cm2 for these two laser generating modes, respectively, correspond to the optimum (in terms of the degree of corrosion resistance) modes of steel treatment. The conducted studies show that the application of Nd: YAG lasers is a promising method for the surface passivation of artworks created from steel and cast iron. One of the most promising applications of the proposed method for the anticorrosion protection of iron is the passivation of the surface of iron-based historical monuments.
]]>Quantum Beam Science doi: 10.3390/qubs6010008
Authors: Sultan Dabagov Alexey Dik
In this review work, the passage of charged and neutral beams through dielectric capillary guides is described from a uniform point of view of beams channeling in capillaries. The motion of beams into the hollow channels formed by the inner walls of capillaries is mainly determined by multiple small-angle scattering (reflection) and can be described in the approximation of surface channeling. It is shown that the surface interaction potential in the case of micro- and nano-capillaries is actually conditioned by the curvature of the reflecting surface. After presenting the analysis of previously performed studies on X-rays propagation into capillaries, which is valid for thermal neutrons, too, the surface channeling formalism is also developed for charged particle beams, in particular, moving in curved cylindrical capillaries. Alternative theories explaining experimental results on the beams passage through capillaries are based on simple thermodynamic estimates, on various diffusion models, and on the results of direct numerical simulations as well. Our work is the first attempt to explain the effective guiding of a charged beam by a capillary from the general standpoint of quantum mechanics, which made it possible to analytically explore the interaction potential for surface channeling. It is established that, depending on the characteristics of a projectile and a dielectric forming the channel, the interaction potential can be either repulsive or attractive; the limiting values of the potential function for the corresponding cases are determined. It has been demonstrated that the surface channeling behaviour can help in explaining the efficient capillary guiding for radiations and beams.
]]>Quantum Beam Science doi: 10.3390/qubs6010007
Authors: Quantum Beam Science Editorial Office Quantum Beam Science Editorial Office
Rigorous peer-reviews are the basis of high-quality academic publishing [...]
]]>Quantum Beam Science doi: 10.3390/qubs6010006
Authors: Toshiaki Kaneko
This paper treats the characteristic topics of MeV/atom cluster ion beams produced using tandem accelerators both in the production stage and in the penetration stage from the viewpoint of fundamental processes. The former is related to atomic collisions in that production and decay of a cluster ion Cn+ (n=1−4) colliding with a charge-changing rare gas underlined through the electron-loss process. Regarding the latter, relatively small carbon clusters Cn+ (n=2−10) are treated. The reduction effect of the average charge of cluster ions in a material is first presented. Next, the electronic stopping power and the energy loss, the polarization force, and the coulomb explosion under cluster-ion impact are described in the dielectric function form. Alignment and structure effects are stressed. As a large and highly symmetric cluster, the electronic stopping power and the average charge are shown for a C60 cluster ion moving inside a solid. Throughout the paper, it is emphasized that the vicinage effect originating from correlation on spatial structure and orientation of constituent ions plays the key role. Moreover, results obtained in cluster production and penetration phenomena are mostly different from multiplication of those under single-ion impact.
]]>Quantum Beam Science doi: 10.3390/qubs6010005
Authors: Atiq Basha Kaligar Hemnath Anandan Kumar Asghar Ali Wael Abuzaid Mehmet Egilmez Maen Alkhader Farid Abed Ali Sami Alnaser
The ever-growing interest in additive manufacturing (AM) is evidenced by its extensive utilisation to manufacture a broad spectrum of products across a range of industries such as defence, medical, aerospace, automotive, and electronics. Today, most laser-based AM is carried out by employing continuous-wave (CW) and long-pulsed lasers. The CW and long-pulsed lasers have the downside in that the thermal energy imparted by the laser diffuses around the irradiated spot and often leads to the creation of heat-affected zones (HAZs). Heat-affected zones may degrade the material strength by producing micro-cracks, porous structures and residual stresses. To address these issues, currently, attempts are being made to employ ultrafast laser sources, such as femtosecond (fs) lasers, in AM processes. Femtosecond lasers with pulse durations in the order of 10−15 s limit the destructive laser–material interaction and, thus, minimise the probability of the HAZs. This review summarises the current advancements in the field of femtosecond laser-based AM of metals and alloys. It also reports on the comparison of CW laser, nanosecond (ns)/picosecond (ps) lasers with fs laser-based AM in the context of heat-affected zones, substrate damage, microstructural changes and thermomechanical properties. To shed light on the principal mechanisms ruling the manufacturing processes, numerical predictions are discussed and compared with the experimental results. To the best of the authors’ knowledge, this review is the first of its kind to encompass the current status, challenges and opportunities of employing fs lasers in additive manufacturing.
]]>Quantum Beam Science doi: 10.3390/qubs6010004
Authors: Hiroshi Amekura Kazumasa Narumi Atsuya Chiba Yoshimi Hirano Keisuke Yamada Shunya Yamamoto Yuichi Saitoh
Quartz (SiO2) crystals possess intrinsic columnar pores perpendicular to (0001) surfaces, consisting of three- and six-membered ring (3MR and 6MR) structures of Si and O atoms. The diameters of the larger pores, i.e., 6 MRs, are ~0.49 nm, while the diameters of fullerene (C60) ions are 0.7 nm, i.e., larger than either type of the pores. Transmission electron microscopy observation evidenced approximately two times longer ion tracks in the channeling condition, i.e., 0° incidence to (0001) surface, than an off-channeling condition, i.e., 7° incidence in this case, under 6 MeV C60 ion injection. The track length at the 0° incidence decreases more steeply than that at the 7° incidence with decreasing the energy from 6 MeV to 1 MeV. Finally, the track lengths at the 0° and 7° incidences become comparable, i.e., the channeling-like effect disappears at 1 MeV irradiation. This study experimentally indicates that the channeling-like effect of C60 ions is induced in quartz crystals, while the sizes of the channels are smaller than the C60 ions.
]]>Quantum Beam Science doi: 10.3390/qubs6010003
Authors: Félix J. Villacorta Damián Martín Rodríguez Mads Bertelsen Heloisa N. Bordallo
To boost the science case of MIRACLES, the time-of-flight backscattering spectrometer at the European Spallation Source (ESS), an optimized neutron guide system, is proposed. This systematic study resulted in an enhancement in the transport of cold neutrons, compared with the previous conceptual design, with wavelengths ranging from λ = 2 Å to 20 Å along the 162.5-m distance from source to sample. This maintained the undisturbed main focus of the instrument, viz, to carry out quasielastic and inelastic neutron scattering (QENS and INS) experiments on a large dynamic range and for both energy-gain and energy-loss sides. To improve the collection of cold neutrons from the source and direct them to the sample position, the vertical geometry was adjusted to an adapted version of a ballistic elliptical profile. Its horizontal geometry was conceived to: (i) keep the high-resolution performance of the instrument, and (ii) minimize the background originating from fast and thermal neutrons. To comply with the first requirement, a narrow guide section at the pulse shaping chopper position has been implemented. To fulfil the second, a curved guide segment has been chosen to suppress neutrons with wavelengths λ < 2 Å. Subsequent tailoring of the phase space provided an efficient transport of cold neutrons along the beamline to reach a 3 × 3 cm2 sample. Finally, additional calculations were performed to present a potential upgrade, with the exchange of the final segment, to focus on samples of approximately 1 × 1 cm2; the proposal anticipates a flux increase of 70% in this 1 cm2 sample area.
]]>Quantum Beam Science doi: 10.3390/qubs6010002
Authors: Shuya Ishii Seiichi Saiki Shinobu Onoda Yuta Masuyama Hiroshi Abe Takeshi Ohshima
Electron beam irradiation into type-Ib diamond is known as a good method for the creation of high concentration negatively-charged nitrogen-vacancy (NV−) centers by which highly sensitive quantum sensors can be fabricated. In order to understand the creation mechanism of NV− centers, we study the behavior of substitutional isolated nitrogen (P1 centers) and NV− centers in type-Ib diamond, with an initial P1 concentration of 40–80 ppm by electron beam irradiation up to 8.0 × 1018 electrons/cm2. P1 concentration and NV− concentration were measured using electron spin resonance and photoluminescence measurements. P1 center count decreases with increasing irradiation fluence up to 8.0 × 1018 electrons/cm2. The rate of decrease in P1 is slightly lower at irradiation fluence above 4.0 × 1018 electrons/cm2 especially for samples of low initial P1 concentration. Comparing concentration of P1 centers with that of NV− centers, it suggests that a part of P1 centers plays a role in the formation of other defects. The usefulness of electron beam irradiation to type-Ib diamonds was confirmed by the resultant conversion efficiency from P1 to NV− center around 12–19%.
]]>Quantum Beam Science doi: 10.3390/qubs6010001
Authors: Akihiro Iwase
Welcome to the Special Issue of Quantum Beam Science entitled “Modifications of Metallic and Inorganic Materials by Using Ion/Electron Beams” [...]
]]>Quantum Beam Science doi: 10.3390/qubs5040034
Authors: Ali Tajyar Noah Holtham Nicholas Brooks Lloyd Hackel Vincent Sherman Ali Beheshti Keivan Davami
In this research, a finite element (FE) technique was used to predict the residual stresses in laser-peened aluminum 5083 at different power densities. A dynamic pressure profile was used to create the pressure wave in an explicit model, and the stress results were extracted once the solution was stabilized. It is shown that as power density increases from 0.5 to 4 GW/cm2, the induced residual stresses develop monotonically deeper from 0.42 to 1.40 mm. However, with an increase in the power density, the maximum magnitude of the sub-surface stresses increases only up to a certain threshold (1 GW/cm2 for aluminum 5083). Above this threshold, a complex interaction of the elastic and plastic waves occurring at peak pressures above ≈2.5 Hugoniot Elastic Limit (HEL) results in decreased surface stresses. The FE results are corroborated with physical experiments and observations.
]]>Quantum Beam Science doi: 10.3390/qubs5040033
Authors: Duong Thanh Tai Truong Thi Hong Loan Abdelmoneim Sulieman Nissren Tamam Hiba Omer David A. Bradley
This work concerns neutron doses associated with the use of a Siemens Primus M5497 electron accelerator, which is operated in the photon mode at 15 MV. The conditions offer a situation within which a fraction of the bremsstrahlung emission energies exceed the photoneutron threshold. For different field sizes, an investigation has been made of neutron dose equivalent values at various measurement locations, including: (i) At the treatment table, at a source-surface distance of 100 cm; (ii) at the level of the floor directly adjacent to the treatment table; and (iii) in the control room and patient waiting area. The evaluated neutron dose equivalent was found to range from 0.0001 to 8.6 mSv/h, notably with the greatest value at the level of the floor directly adjacent to the treatment couch (8.6 mSv/h) exceeding the greatest value on the treatment table (5.5 mSv/h). Low values ranging from unobservable to between 0.0001 to 0.0002 mSv/h neutron dose were recorded around the control room and patient waiting area. For measurements on the floor, the study showed the dose equivalent to be greatest with the jaws closed. These data, most particularly concerning neutron distribution within the treatment room, are of great importance in making steps towards improving patient safety via the provision of protective measures.
]]>Quantum Beam Science doi: 10.3390/qubs5040032
Authors: Yasushi Sasajima Ryuichi Kaminaga Norito Ishikawa Akihiro Iwase
The nanopore formation process that occurs by supplying a thermal spike to single crystal CeO2 has been simulated using a molecular dynamics method. As the initial condition, high thermal energy was supplied to the atoms in a nano-cylinder placed at the center of a fluorite structure. A nanopore was generated abruptly at around 0.3 ps after the irradiation, grew to its maximum size at 0.5 ps, shrank during the time to 1.0 ps, and finally equilibrated. The nanopore size increased with increasing effective stopping power gSe (i.e., the thermal energy deposited per unit length in the specimen), but it became saturated when gSe was 0.8 keV/nm or more. This finding will provide useful information for precise control of the size of nanopores. Our simulation confirmed nanopore formation found in the actual experiment, irradiation of CeO2 with swift heavy ions, but could not reproduce crystalline hillock formation just above the nanopores.
]]>Quantum Beam Science doi: 10.3390/qubs5040031
Authors: Seth Eckels Zayed Ahmed Molly Ross Daniel Franken Steven Eckels Hitesh Bindra
Recent studies have shown that the presence of dissolved salts in water can exhibit peculiar flow boiling and two-phase flow regimes. Two-phase flow and convective flow boiling are typically characterized with the help of void fraction measurements. To quantitatively improve our understanding of two-phase flow and boiling phenomenon with seawater coolant, void fraction data are needed, which can not be obtained from optical imaging. In this paper, we present experimental void fraction measurements of saturated flow boiling of tap water and seawater using X-ray radiography. X-rays with a maximum energy level of 40 KeV were used for imaging the exit region of the heated test section. At lower heat flux levels, the two phase flow in seawater was bubbly and homogeneous in nature, resulting in higher void fractions as compared to tap water. With an increase in heat flux, the flow regime was similar to slug flow, and void fraction measurements approached similarity with tap water. The predicted pressure drop using the measured void faction shows good agreement with the measured total pressure drop across the test section, demonstrating the validity of the measurement process.
]]>Quantum Beam Science doi: 10.3390/qubs5040030
Authors: Noriaki Matsunami Masao Sataka Satoru Okayasu Bun Tsuchiya
It has been known that the modification of non-metallic solid materials (oxides, nitrides, etc.), e.g., the formation of tracks, sputtering representing atomic displacement near the surface and lattice disordering are induced by electronic excitation under high-energy ion impact. We have investigated lattice disordering by the X-ray diffraction (XRD) of SiO2, ZnO, Fe2O3 and TiN films and have also measured the sputtering yields of TiN for a comparison of lattice disordering with sputtering. We find that both the degradation of the XRD intensity per unit ion fluence and the sputtering yields follow the power-law of the electronic stopping power and that these exponents are larger than unity. The exponents for the XRD degradation and sputtering are found to be comparable. These results imply that similar mechanisms are responsible for the lattice disordering and electronic sputtering. A mechanism of electron–lattice coupling, i.e., the energy transfer from the electronic system into the lattice, is discussed based on a crude estimation of atomic displacement due to Coulomb repulsion during the short neutralization time (~fs) in the ionized region. The bandgap scheme or exciton model is examined.
]]>Quantum Beam Science doi: 10.3390/qubs5040029
Authors: Kaitlin Hellier Emmie Benard Christopher C. Scott Karim S. Karim Shiva Abbaszadeh
Amorphous selenium (a-Se) is a glass-former capable of deposition at high rates by thermal evaporation over a large area. It was chosen as a direct conversion material due to its appealing properties for imaging in both low and high X-ray energy ranges (<30 keV and <30 keV, respectively). It has a bandgap of 2.2 eV and can achieve high photodetection efficiency at short wavelengths less than 400 nm which makes it appealing for indirect conversion detectors. The integration of a-Se with readout integrated circuits started with thin-film transistors for digital flat panel X-ray detectors. With increasing applications in life science, biomedical imaging, X-ray imaging, high energy physics, and industrial imaging that require high spatial resolution, the integration of a-Se and CMOS is one direct way to improve the high-contrast visualization and high-frequency response. Over the past decade, significant improvements in a-Se/CMOS technologies have been achieved with improvements to modulation transfer function and detective quantum efficiency. We summarize recent advances in integrating and photon-counting detectors based on a-Se coupled with CMOS readout and discuss some of the shortcomings in the detector structure, such as low charge conversion efficiency at low electric field and high dark current at high electric field. Different pixel architectures and their performance will be highlighted.
]]>Quantum Beam Science doi: 10.3390/qubs5040028
Authors: Amith Anil Sufal Swaraj Sankaran Subramanian Praveen Ramamurthy
Scanning transmission X-ray microscopy (STXM) was utilized for analysing the bioremediation of Cr(VI) by Citrobacter freundii, a species of gram-negative bacteria. The biosorption and bioreduction processes were analysed by the chemical mapping of cells biosorbed at different concentrations of Cr(VI). STXM spectromicroscopy images were recorded at O K-edge and Cr L-edge. A thorough analysis of the X-ray absorption features corresponding to different oxidation states of Cr in the biosorbed cell indicated the coexistence of Cr(III) and Cr(VI) at higher concentrations. This signifies the presence of partially reduced Cr(VI) in addition to biosorbed Cr(VI). In addition, the Cr(III) signal is intense compared with Cr(VI) at different regions of the cell indicating excess of reduced Cr. Speciation of adsorbed Cr was analysed for the spectral features of biosorbed cell and comparison with Cr standards. Analysis of absorption onset, L3/L2 ratio and absorption fine structure concludes that adsorbed Cr is predominantly present as Cr(III) hydroxide or oxyhydroxide. The evolution of absorption features in the duration of biosorption process was also studied. These time lapse studies depict the gradual decrement in Cr(VI) signal as biosorption proceeds. A strong evidence of interaction of Cr with the cell material was also observed. The obtained results provide insights into the biosorption process and chemical speciation of Cr on the cells.
]]>Quantum Beam Science doi: 10.3390/qubs5030027
Authors: Nariaki Okubo Yuki Fujimura Masakatsu Tomobe
In an accelerator-driven system (ADS), the beam window material of the spallation neutron target is heavily irradiated under severe conditions, in which the radiation damage and corrosion co-occur because of high-energy neutron and/or proton irradiation in the lead–bismuth flow. The materials used in ADSs must be compatible with the liquid metal (lead–bismuth eutectic (LBE)) to prevent issues such as liquid metal embrittlement (LME) and liquid metal corrosion (LMC). This study considers the LMC behavior after ion irradiation of 316L austenitic steel for self-ion irradiations followed by the corrosion tests in LBE with critical oxygen concentration. The 316L samples were irradiated by 10.5 MeV-Fe3+ ions at a temperature of 450 °C, up to 50 displacements per atom (dpa). After the corrosion test performed at 450 °C in LBE with low oxygen concentration, a surface of the nonirradiated area was not oxidized but appeared with locally corrosive morphology, Ni depletion, whereas an iron/chromium oxide layer fully covered the irradiated area. In the case of the corrosion surface with high oxygen concentration in LBE, the surface of the nonirradiated area was covered by an iron oxide layer only, whereas the irradiated area was covered by the duplex layers comprising iron and iron/chromium oxides. It is suggested that irradiation can enhance the oxide layer formation because of the enhancement of Fe and/or oxygen diffusion induced by the radiation defects in 316L steel.
]]>Quantum Beam Science doi: 10.3390/qubs5030026
Authors: Ken-ichi Fukumoto Shuichiro Miura Yoshiki Kitamura Ryoya Ishigami Takuya Nagasaka
V–4Cr–xTi (x = 0 to 4) alloys were used to investigate the additional effect of Cr, Ti and interstitial impurities on the microstructural evolution in He-irradiated V–Cr–Ti alloys to minimize radioactivity after fusion neutron irradiation. Transmission electron microscopy and atom probe tomography were carried out to the He-irradiated specimens at 500 °C with 0.5 dpa at peak damage. A flash electro-polishing method for the FIB-extracted specimen was established for the ion-irradiated vanadium alloys. The microstructural evolution of the irradiation-induced titanium-oxycarbonitride, Ti(CON) precipitates was observed and was influenced by the effect of Ti addition on the Ti(CON) precipitation. Apparent Ti(CON) precipitates formed in V-4Cr-xTi with 2% addition of Ti. In the V-4Cr-1Ti alloy, a high density Ti enriched cluster was formed. The origin of the irradiation hardening increase resulted from the size distribution of Ti(CON) precipitation from the dispersed barrier-hardening theory.
]]>Quantum Beam Science doi: 10.3390/qubs5030025
Authors: Yoshihiro Hase Katsuya Satoh Atsuya Chiba Yoshimi Hirano Kengo Moribayashi Kazumasa Narumi
The unique energy transfer characteristics of swift cluster ions have attracted the attention of many researchers working on the analysis or processing of material surfaces, but the effects on living organisms remain unclear. We irradiated B. subtilis spores with monomer and cluster proton beams and examined their lethality; the 2 MeV H2+ shows a clearly lower lethality than 340 keV H+, even though both have a comparable linear energy transfer. The 2 MeV H2+ dissociates into a pair of 1 MeV H+ by losing the bonding electrons at the target surface. The estimated internuclear distance and the radial dose distribution suggest that the spread of deposited total energy over two areas separated by just several nanometers greatly diminishes beam lethality and that the energy density in the very center of the trajectory, possibly within a 1 nm radius, has a great impact on lethality. We also performed a whole genome resequencing of the surviving colonies to compare the molecular nature of mutations but failed to find a clear difference in overall characteristics. Our results suggest that cluster beams may be a useful tool for understanding biological effects of high linear energy transfer radiation.
]]>Quantum Beam Science doi: 10.3390/qubs5030024
Authors: William F. Cureton Cameron L. Tracy Maik Lang
During the final production steps after the proofreading of this paper [...]
]]>Quantum Beam Science doi: 10.3390/qubs5030023
Authors: Shun-Ichiro Tanaka
I have proposed a bottom-up technology utilising irradiation with active beams, such as electrons and ions, to achieve nanostructures with a size of 3–40 nm. This can be used as a nanotechnology that provides the desired structures, materials, and phases at desired positions. Electron beam irradiation of metastable θ-Al2O3, more than 1019 e/cm2s in a transmission electron microscope (TEM), enables the production of oxide-free Al nanoparticles, which can be manipulated to undergo migration, bonding, rotation, revolution, and embedding. The manipulations are facilitated by momentum transfer from electrons to nanoparticles, which takes advantage of the spiral trajectory of the electron beam in the magnetic field of the TEM pole piece. Furthermore, onion-like fullerenes and intercalated structures on amorphous carbon films are induced through catalytic reactions. δ-, θ-Al2O3 ball/wire hybrid nanostructures were obtained in a short time using an electron irradiation flashing mode that switches between 1019 and 1022 e/cm2s. Various α-Al2O3 nanostructures, such as encapsulated nanoballs or nanorods, are also produced. In addition, the preparation or control of Pt, W, and Cu nanoparticles can be achieved by electron beam irradiation with a higher intensity.
]]>Quantum Beam Science doi: 10.3390/qubs5030022
Authors: Raphael Finger Thomas C. Hansen Holger Kohlmann
A gas-pressure cell, based on a leuco-sapphire single-crystal, serving as a pressure vessel and sample holder, is presented for real time in situ studies of solid-gas hydrogenation reactions. A stainless steel corpus, coated with neutron absorbing varnish, allows alignment for the single-crystal sample holder for minimizing contributions to the diffraction pattern. Openings in the corpus enable neutron scattering as well as contactless temperature surveillance and laser heating. The gas-pressure cell is validated via the deuteration of palladium powder, giving reliable neutron diffraction data at the high-intensity diffractometer D20 at the Institut Laue-Langevin (ILL), Grenoble, France. It was tested up to 15.0 MPa of hydrogen pressure at room temperature, 718 K at ambient pressure and 584 K at 9.5 MPa of hydrogen pressure.
]]>Quantum Beam Science doi: 10.3390/qubs5030021
Authors: Yuma Sato Hiroshi Koshikawa Shunya Yamamoto Masaki Sugimoto Shin-ichi Sawada Tetsuya Yamaki
The micro/nanocone structures of noble metals play a critical role as heterogeneous electrocatalysts that provide excellent activity. We successfully fabricated platinum cones by electrodeposition using non-penetrated porous membranes as templates. This method involved the preparation of template membranes by the swift-heavy-ion irradiation of commercially available polycarbonate films and subsequent chemical etching in an aqueous NaOH solution. The surface diameter, depth, aspect ratio and cone angle of the resulting conical pores were controlled in the ranges of approximately 70–1500 nm, 0.7–11 μm, 4–12 and 5–13°, respectively, by varying the etching conditions, which finally produced size- and shape-controlled platinum cones with nanotips. In order to demonstrate the electrocatalytic activity, electrochemical measurements were performed for the ethanol oxidation reaction. The oxidation activity was found to be up to 3.2 times higher for the platinum cone arrays than for the platinum plate. Ion-track etching combined with electrodeposition has the potential to be an effective method for the fabrication of micro/nanocones with high electrocatalytic performance.
]]>Quantum Beam Science doi: 10.3390/qubs5030020
Authors: Yasuki Okuno Nariaki Okubo
Partially stabilized zirconia (PSZ) is considered for use as an oxygen-sensor material in liquid lead-bismuth eutectic (LBE) alloys in the radiation environment of an acceleration-driven system (ADS). To predict its lifetime for operating in an ADS, the effects of radiation on the PSZ were clarified in this study. A tetragonal PSZ was irradiated with 100 keV electrons and analyzed by X-ray diffraction (XRD). The results indicate that the phase transition in the PSZ, from the tetragonal to the monoclinic phase, was caused after the irradiation. The deposition energy of the lattice and the deposition energy for the displacement damage of a 100 keV electron in the PSZ are estimated using the particle and heavy ion transport code system and the non-ionizing energy loss, respectively. The results suggest that conventional radiation effects, such as stopping power, are not the main mechanism behind the phase transition. The phase transition is known to be caused by the low-temperature degradation of the PSZ and is attributed to the shift of oxygen ions to oxygen sites. When the electron beam is incident to the material, the kinetic energy deposition and excitation-related processes are caused, and it is suggested to be a factor of the phase transition.
]]>Quantum Beam Science doi: 10.3390/qubs5020019
Authors: William F. Cureton Cameron L. Tracy Maik Lang
Cerium dioxide (CeO2) exhibits complex behavior when irradiated with swift heavy ions. Modifications to this material originate from the production of atomic-scale defects, which accumulate and induce changes to the microstructure, chemistry, and material properties. As such, characterizing its radiation response requires a wide range of complementary characterization techniques to elucidate the defect formation and stability over multiple length scales, such as X-ray and neutron scattering, optical spectroscopy, and electron microscopy. In this article, recent experimental efforts are reviewed in order to holistically assess the current understanding and knowledge gaps regarding the underlying physical mechanisms that dictate the response of CeO2 and related materials to irradiation with swift heavy ions. The recent application of novel experimental techniques has provided additional insight into the structural and chemical behavior of irradiation-induced defects, from the local, atomic-scale arrangement to the long-range structure. However, future work must carefully account for the influence of experimental conditions, with respect to both sample properties (e.g., grain size and impurity content) and ion-beam parameters (e.g., ion mass and energy), to facilitate a more direct comparison of experimental results.
]]>Quantum Beam Science doi: 10.3390/qubs5020018
Authors: Toshinori Ozaki Takuya Kashihara Itsuhiro Kakeya Ryoya Ishigami
Raising the critical current density Jc in magnetic fields is crucial to applications such as rotation machines, generators for wind turbines and magnet use in medical imaging machines. The increase in Jc has been achieved by introducing structural defects including precipitates and vacancies. Recently, a low-energy ion irradiation has been revisited as a practically feasible approach to create nanoscale defects, resulting in an increase in Jc in magnetic fields. In this paper, we report the effect of proton irradiation with 1.5 MeV on superconducting properties of iron–chalcogenide FeSe0.5Te0.5 films through the transport and magnetization measurements. The 1.5 MeV proton irradiation with 1 × 1016 p/cm2 yields the highest Jc increase, approximately 30% at 5–10 K and below 1 T without any reduction in Tc. These results indicate that 1.5 MeV proton irradiations could be a practical tool to enhance the performance of iron-based superconducting tapes under magnetic fields.
]]>Quantum Beam Science doi: 10.3390/qubs5020017
Authors: Takahisa Shobu Ayumi Shiro Fumiaki Kono Toshiharu Muramatsu Tomonori Yamada Masayuki Naganuma Takayuki Ozawa
The automotive industries employ laser beam welding because it realizes a high energy density without generating irradiation marks on the opposite side of the irradiated surface. Typical measurement techniques such as strain gauges and tube X-rays cannot assess the localized strain at a joint weld. Herein high-energy synchrotron radiation X-ray diffraction was used to study the internal strain distribution of laser lap joint PNC-FMS steels (2- and 5-mm thick) under loading at a high temperature. As the tensile load increased, the local tensile and compressive strains increased near the interface. These changes agreed well with the finite element analysis results. However, it is essential to complementarily utilize internal defect observations by X-ray transmission imaging because the results depend on the defects generated by laser processing.
]]>Quantum Beam Science doi: 10.3390/qubs5020016
Authors: Tetsuro Sueyoshi
The critical current density Jc, which is a maximum value of zero-resistivity current density, is required to exhibit not only larger value but also lower anisotropy in a magnetic field B for applications of high-Tc superconductors. Heavy-ion irradiation introduces nanometer-scale irradiation tracks, i.e., columnar defects (CDs) into high-Tc superconducting materials, which can modify both the absolute value and the anisotropy of Jc in a controlled manner: the unique structures of CDs, which significantly affect the Jc properties, are engineered by adjusting the irradiation conditions such as the irradiation energy and the incident direction. This paper reviews the modifications of the Jc anisotropy in high-Tc superconductors using CDs installed by heavy-ion irradiations. The direction-dispersion of CDs, which is tuned by the combination of the plural irradiation directions, can provide a variety of the magnetic field angular variations of Jc in high-Tc superconductors: CDs crossing at ±θi relative to the c-axis of YBa2Cu3Oy films induce a broad peak of Jc centered at B || c for θi < ±45°, whereas the crossing angle of θi ≥ ±45° cause not a Jc peak centered at B || c but two peaks of Jc at the irradiation angles. The anisotropy of Jc can also modified by tuning the continuity of CDs: short segmented CDs formed by heavy-ion irradiation with relatively low energy are more effective to improve Jc in a wide magnetic field angular region. The modifications of the Jc anisotropy are discussed on the basis of both structures of CDs and flux line structures depending on the magnetic field directions.
]]>Quantum Beam Science doi: 10.3390/qubs5020015
Authors: Mitsuru Imaizumi Takeshi Ohshima Yosuke Yuri Kohtaku Suzuki Yoshifumi Ito
We investigated the effects of irradiation beam conditions on the performance degradation of silicon and triple-junction solar cells for use in space. The fluence rates of electron and proton beams were varied. Degradation did not depend on the fluence rate of protons for both cells. A higher fluence rate of electrons caused greater degradation of the Si cell, but the dependence was due to the temperature increase during irradiation. Two beam-area expansion methods, defocusing and scanning, were examined for proton irradiation of various energies (50 keV–10 MeV). In comparing the output degradation from irradiation with defocused and scanned proton beams, no significant difference in degradation was found for any proton energy. We plan to reflect these findings into ISO standard of irradiation test method of space solar cells.
]]>Quantum Beam Science doi: 10.3390/qubs5020014
Authors: Satoshi Hatori Ryoya Ishigami Kyo Kume Kohtaku Suzuki
The core facility of the Wakasa Wan Energy Research Center (WERC) consists of three ion accelerators: a synchrotron, a tandem accelerator and an ion-implanter. Research on the irradiation effects using these accelerators has been performed on space electronics such as solar cells, radiation detectors, image sensors and LSI circuits. In this report, the accelerator facility and ion-irradiation apparatuses at WERC are introduced, focusing on the research on irradiation effects on space electronics. Then, some recent results are summarized.
]]>