Quantum Beam Sci., Volume 7, Issue 3 (September 2023) – 9 articles

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. Full article

The existing experimental data for the $\gamma$ decay of the stable $N=Z$ doubly-odd nuclei and the $\beta$ decay of the corresponding isospin multiplets is reviewed. The structure of the lightest nuclei with masses $A\le 14$ 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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article

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. Full article