Search Results (98)

Background: Environmental ionizing radiation plays a major role in human radiation exposure. Natural background radiation originates from the Earth’s crust and outer space. The terrestrial component consists of primordial radioisotopes (⁴⁰K, ²³⁸U, ²³⁵U, ²³²Th), as well as elements of the uranium and thorium decay chains, of which, from a dosimetric perspective, ²²²Rn and its decay products carry the greatest weight. These account for more than half of the crustal component. Cosmic radiation consists of gamma rays, X-rays, and particles such as protons, electrons, neutrons, mesons, and hyperons. Methods: The main objective of our research is to determine the background radiation levels characteristic of various regions of Transylvania. In addition, we aim to determine the effects of local environmental, diurnal, and seasonal changes on radiation levels. Results: A statistically significant difference was observed between the values of the individual regions (p < 0.001). The values we measured ranged from 0.051 µSv/h to 0.285 µSv/h. Based on the results, we can conclude that there is a statistically significant difference (p < 0.05) between the median value dropped after ventilation (0.159 µSv/h), compared to the one before ventilation (0.164 µSv/h). According to our database, radiation levels are significantly (p < 0.01) higher during the fall and winter months. Conclusions: On this basis, Transylvania can be regarded as a safe and livable region in terms of natural background radiation levels. Nevertheless, it is important to maintain a healthy lifestyle, ventilate homes frequently, and spend as much time as possible outdoors in nature. Full article

The increasing demand for ion beams heavier than protons—particularly carbon and helium ions—for cancer therapy has driven the development of advanced accelerator technologies. Although proton therapy is well established, its physical properties limit its effectiveness against certain tumor types, thereby motivating the use of ions with higher linear energy transfer (LET) and greater biological effectiveness. This study presents the design of an Alvarez-type linear accelerator configuration that combines a Quasi-Alvarez Drift Tube Linac (QA-DTL) and a conventional Alvarez Drift Tube Linac (DTL). The proposed systems are intended for accelerating and injecting carbon or helium ions into a cancer therapy synchrotron, as well as accelerating helium ions for radioisotope production. The optimized QA-DTL and DTL structures provide a versatile and efficient solution for future particle therapy facilities, addressing the growing demand for compact, high-performance, and multifunctional accelerator systems. The proposed linac configurations are designed to operate at 352.2 MHz and consist of three sections. For accelerating low-velocity ions, the first section is a QA-DTL, which is the only section powered during the injection of carbon or helium ions (depending on configuration) into the therapy synchrotron at the energy of 5 MeV/u. The QA-DTL is followed by two DTL cavities forming the second and third sections, which further accelerate helium ions to energies of up to 7.1 MeV/u and 10 MeV/u, respectively. The energy of 7.1 MeV/u is chosen because it represents the production threshold of ²¹¹At, one of the most promising alpha emitters for targeted alpha therapy. Full article

Alpha spectrometry is a useful method for measuring alpha emitters in all types of samples and for all types of radioisotopes, both artificial and natural. The high activity concentration of TENORM industries’ by-products and their management are of great concern; however, due to the high activity and the complex matrixes of these types of wastes, there are overlaps between peaks and an acute activity determination can require a high consumption of time and material. To diminish it and obtain a proper activity evaluation, spectra deconvolution has been carried out using a genetic algorithm to fit the selected function to experimental data. This algorithm uses the analyst’s visualization of the observed experimental spectrum as a reference and adapts the fitting parameters to the observed peak. This gives the algorithm great capacity to adapt to different spectra obtained experimentally. The results of its application to different TENORM samples have been very satisfactory, including complicated multi-energetic alpha emitters such as Th-229. Full article

Diagnosis and endoradiotherapy using copper radioisotopes—defined as Theranostics or, more specifically, CopperNostics—have the potential to play a prominent role in modern precision medicine, as demonstrated by the FDA approval of [⁶⁴Cu]Cu-DOTA-TATE (Detectnet). In this review we highlight current developments in the production, radiochemical purification, quality control, availability, logistics, and regulatory hurdles of the most relevant copper radioisotopes, ⁶⁰Cu, ⁶¹Cu, ⁶²Cu, ⁶⁴Cu, and ⁶⁷Cu, for nuclear medicine. Radiopharmaceuticals based on their application in registered clinical trials, either as molecular imaging agents, companion diagnostics or therapeutic agents, are also presented addressing unmet medical needs. Full article

Thorium carbide (${\mathrm{ThC}}_{2\pm x}$) nano-structured thin disc-like pellets were produced from thoria nanoparticles (${\mathrm{ThO}}_2$-NP) and multi-walled carbon nanotubes (MWCNT). These composites are to be studied as a target material candidate for radioactive ion beam (RIB) production via nuclear reactions upon impact with high-energy proton beams on a stack of solid pellets. The ${\mathrm{ThO}}_2$-NP precursor was produced via precipitation of thorium oxalate from a thorium nitrate solution with oxalic acid and subsequent hydrothermal oxidation of the oxalate, creating the thoria nanoparticles. The ${\mathrm{ThO}}_2$-NP were then mixed with MWCNT in isopropyl alcohol and sonicated by two different methods to create a nanoparticle dispersion. This dispersion was then heated under medium vacuum to evaporate the solvent; the resulting powder was pressed into pellets and taken to an inert-atmosphere oven, where it was heated to 1650 °C and carbothermally reduced to ${\mathrm{ThC}}_{2\pm x}$. The resulting pellets were characterized via XRD, SEM-EDS, and Raman spectroscopy. The resulting thorium pellets exhibited, at most, trace levels of the oxide precursor. Furthermore, the nanotube structures were still present in the final product and are expected to contribute positively towards faster radioisotope release times by lowering isotope diffusion times, which is required for the efficient extraction of the shortest-lived (<1 s half-life) radioisotopes. Full article

Zirconium-89 (⁸⁹Zr) is a widely used radionuclide in immune-PET imaging due to its physical decay characteristics. Despite its importance, the production of ⁸⁹Zr radiopharmaceuticals remains largely manual, with limited cost-effective automation solutions available. To address this, we developed an automated system for the agile and reliable production of radiopharmaceuticals. The system performs transmutations, dissolution, and separation for a range of radioisotopes. Steps in the production of ⁸⁹Zr-oxalate are used as an exemplar to illustrate its use. Three-dimensional (3D) printing was exploited to design and manufacture a target holder able to include solid targets, in this case an ⁸⁹Y foil. Spot welding was used to attach ⁸⁹Y to a refractory tantalum (Ta) substrate. A commercially available CPU chiller was repurposed to efficiently cool the metal target. Furthermore, a commercial resin (ZR Resin) and compact peristaltic pumps were employed in a compact (10 × 10 × 10 cm³) chemical separation unit that operates automatically via computer-controlled software. Additionally, a standalone 3D-printed unit was designed with three automated functionalities: photolabelling, vortex mixing, and controlled heating. All components of the assembly, except for the target holder, are housed inside a commercially available hot cell, ensuring safe and efficient operation in a controlled environment. This paper details the design, construction, and modelling of the entire assembly, emphasising its innovative integration and operational efficiency for widespread radiopharmaceutical automation. Full article

High-current electron beams can significantly enhance the productivity of variety of applications including medical radioisotope (RI) production and wastewater purification. High-power superconducting radio frequency (SRF) linacs are capable of producing such high-current electron beams due to the key advantage to operate in continuous wave (CW) mode. However, this requires an injector capable of generating electron bunches with high repetition rate and in CW mode, while minimizing beam losses to avoid damage to SRF cavities due to quenching. RF gating to the grid of a thermionic electron gun is a promising solution, as it ensures CW bunch generation at the repetition rate same as the fundamental or sub-harmonics of the accelerating RF frequency, with minimal beam loss. This paper presents detailed beam dynamics simulations demonstrating that an RF-gated gun operating at 1.3 GHz can generate bunches with 148 ps full width with 8.96 pC charge. Full article

In this work, hybrid membranes were fabricated by depositing polyvinyl chloride (PVC) fibers onto PET track-etched membranes (TeMs) using the electrospinning technique. The resulting structures exhibited enhanced hydrophobicity, with contact angles reaching 155°, making them suitable for applications in both water–oil mixture separation and membrane distillation processes involving low-level liquid radioactive waste (LLLRW), saline solutions, and natural water sources. The use of hybrids of TeMs and nanofiber membranes has significantly increased productivity compared to TeMs only, while maintaining a high degree of purification. Permeate obtained after MD of LLLRW and river water was analyzed by conductometry and the atomic emission spectroscopy (for Sr, Cs, Al, Mo, Co, Sb, Ca, Fe, Mg, K, and Na). The activity of radioisotopes (for ¹²⁴Sb, ⁶⁵Zn, ⁶⁰Co, ⁵⁷Co, ¹³⁷Cs, and ¹³⁴Cs) was evaluated by gamma-ray spectroscopy. In most cases, the degree of rejection was between 95 and 100% with a water flux of up to 17.3 kg/m²·h. These membranes were also tested in the separation of cetane–water emulsion with productivity up to 47.3 L/m²·min at vacuum pressure of 700 mbar and 15.2 L/m²·min at vacuum pressure of 900 mbar. Full article

At the Radiopharmaceutical Research Center (CCR) of the Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), we operate a TR-19 cyclotron for radio isotope production. To broaden our spectrum of radioisotopes with applications in nuclear medicine, we add a new external beam line towards a state-of-the-art solid target station. Besides practical experience with the implementation of the Comecer ALCEO metal solid targetry system, a new, more efficient way of tuning the beam onto the target and the design of a dedicated neutron local layered shielding are presented. Full article

This paper focuses on the highly radioactive, long-lasting nuclear waste produced by the currently operating fission reactors and on the sensitive issue of spent fuel reprocessing. Also included is a short description of the fission process and a detailed analysis of the more hazardous radioisotopes produced either by secondary reactions occurring in the nuclear installations or by decay of the fission fragments. The review provides an overview of the strategies presently adopted to minimize the harmfulness of the nuclear waste to be disposed, with a focus on the development and implementation of methodologies for the spent fuel treatments. The partitioning-conditioning and partitioning-transmutation options are analyzed as possible solutions to decrease the presence of long-lived highly radioactive isotopes. Also discussed are the chemical/physical approaches proposed for the recycling of the spent fuel and for the reusing of some technologically relevant isotopes in industrial and pharmaceutical areas. A brief indication is given of the opportunities offered by innovative types of reactors and/or of new fuel cycles to solve the issues presently associated with radioactive waste. Full article

The implementation of the Variable Energy (VE) feature in the previously fixed-energy IBA Cyclone^® Kiube cyclotron is presented as an upgrade enabling the production of novel radioisotopes with improved radionuclidic purity and production yields. The possibility of easily decreasing the energy of the extracted proton beam, from 18 down to 13 MeV, allows us to avoid the use of degraders and/or thick target windows, thus preventing related beam current limitations. The immediate application of the Variable Energy feature is proven by presenting the improved results obtained for the production of ⁶⁸Ga from the irradiation of liquid targets simultaneously in terms of radionuclidic purity and activity produced. Full article

An algorithm based on continuous measurement of multiphase flows of oil well production has been designed to improve the efficiency of the technical control of oil production processes in the field. Separation-free, non-contact measurement of multiphase flows of oil well products allows increasing the efficiency of managing oil production processes in the field. Monitoring the current density using radioisotope measuring transducers (RMTs) allows obtaining information about the structure of the flow in the form of the distribution of gas inclusions and the speed of movement of liquid and gas in a two-phase flow. Fluid velocity measurement is based on digital processing of RMT signals, applying a continuous or discrete undecimated wavelet transform to them, and assessing the cross-correlation of wavelet coefficients in individual subspaces of the wavelet decomposition. The cross-correlation coefficients of two RMT signals located at a base distance, calculated in the subspaces of the wavelet decomposition, characterize the speed of movement of gas bubbles of different sizes in a vertical pipe. The measurement assumes that the velocity of the liquid phase of the oil flow in a vertical pipe mainly corresponds to the velocity of small bubbles. This speed should be determined by the maximum cross-correlation of wavelet coefficients in the corresponding decomposition subspace. Computer modeling made it possible to evaluate the characteristics of the algorithm for controlling the speed of liquid movement in the gas–liquid flow of oil well products and determine the mass flow rate of the liquid and the relative value of the gas content. The implementation of the algorithm in a multi-channel version of the device allows monitoring an entire cluster of wells in the field. Full article

The present work promotes and validates the benefits of using niobium instead of Havar^® as the material for the target windows in most routine irradiations in cyclotrons. Calculation of the material activation and measurements of the contamination of the transferred target liquids show major improvements with the use of niobium. Also, the data of the daily routine productions at our production center are presented, proving that Havar^® is not mandatory unless large target currents and/or pressures are required. Full article

On the verge of a theranostic approach to personalised medicine, copper-64 is one of the emerging radioisotopes in nuclear medicine due to its exploitable nuclear and biochemical characteristics. The increased demand for copper-64 for preclinical and clinical studies has prompted the development of production routes. This research aims to compare the (p,n) reaction on nickel-64 solid versus liquid targets and evaluate the effectiveness of [⁶⁴Cu]CuCl₂ solutions prepared by the two routes. As new treatments for neurotensin receptor-overexpressing tumours have developed, copper-64 was used to radiolabel Neurotensin (8-13) and Neuromedin N. High-quality [⁶⁴Cu]CuCl₂ solutions were prepared using ACSI TR-19 and IBA Cyclone Kiube cyclotrons. The radiochemical purity after post-irradiation processing reached 99% (LT) and 99.99% (ST), respectively. The irradiation of a solid target with 11.8 MeV protons and 150 μAh led to 704 ± 84 MBq/μA (17.6 ± 2.1 GBq/batch at EOB). At the end of the purification process (1 h, 90.90% activity yield), the solution for peptide radiolabelling had a radioactive concentration of 1340.4 ± 70.1 MBq/mL (n.d.c.). The irradiation of a liquid target with 16.9 MeV protons and 230 μAh resulted in 3.7 ± 0.2 GBq/batch at EOB, which corresponds to an experimental production yield of 6.89 GBq.cm3/(g.µA)_sat. Benefiting from a shorter purification process (40 min), the activity yielded 90.87%, while the radioactive concentration of the radiolabelling solution was lower (492 MBq/mL, n.d.c.). The [⁶⁴Cu]CuCl₂ solutions were successfully used for the radiolabelling of DOTA-NT(8-13) and DOTA-NN neuropeptides, resulting in a high RCP (>99%) and high molar activity (27.2 and 26.4 GBq/μmol for LT route compared to 45 and 52 GBq/μmol for ST route, respectively). The strong interaction between the [⁶⁴Cu]Cu-DOTA-NT(8-13) and the colon cancerous cell lines HT29 and HCT116 proved that the specificity for NTR had not been altered, as shown by the uptake and retention data. Full article

A new Center for Radiopharmaceutical Cancer Research was established at the Helmholtz-Zentrum Dresden-Rossendorf in 2017 to centralize radionuclide and radiopharmaceutical production, as well as enable chemical and biochemical research. Routine production of several radionuclides was put into operation in recent years. We report on the production methods of radiopharmaceutical radionuclides, in particular ¹¹C, ¹⁸F, and radio metals like ⁶¹Cu, ⁶⁴Cu, ⁶⁷Cu, ⁶⁷Ga, ¹³¹Ba, and ¹³³La that are used regularly. In the discussion, we report typical irradiation parameters and achieved saturation yields. Full article