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Neutron and γ-ray irradiation damages to transistors are found to be non-additive, and this is denoted as the irradiation synergistic effect (ISE). Its mechanism is not well-understood. The recent defect-based model [Song and Wei, ACS Appl. Electron. Mater. 2, 3783 (2020)] for silicon bipolar junction transistors (BJTs) achieves quantitative agreement with experiments, but its assumptions on the defect reactions are unverified. Going beyond the model requires directly representing the effect of γ-ray irradiation in first-principles calculations, which was not feasible previously. In this work, we examine the defect-based model of the ISE by developing a multiscale method for the simulation of the γ-ray irradiation, where the γ-ray-induced electronic excitations are treated explicitly in excited-state first-principles calculations. We find the calculations agree with experiments, and the effect of the γ-ray-induced excitation is significantly different from the effects of defect charge state and temperature. We propose a diffusion-based qualitative explanation of the mechanism of positive/negative ISE in NPN/PNP BJTs in the end. [ABSTRACT FROM AUTHOR]

Neutron irradiation causes embrittlement of reactor pressure vessel (RPV) steels. Post-irradiation annealing is capable of partly or fully restoring the unembrittled condition. While annealing at high temperatures (e.g., 475°C) was successfully applied to extend the lifetime of operating VVER-440 reactors, the benefit of annealing at lower temperatures (e.g., 343°C-the maximum to which the primary cooling water can be heated) is a matter of debate. In this study, neutron-irradiated VVER-440 RPV base metal and weld were exposed to isothermal annealing at 343°C up to 2,000 h. Given the limited amount of material, the degree of recovery was estimated in terms of Vickers hardness, the ductile-brittle transition temperature derived from small punch tests, and the master curve reference temperature derived from fracture mechanics tests of mini samples. For the base metal, small-angle neutron scattering was applied to underpin the findings at the nm-scale. We have found significant partial recovery in both materials after annealing for 300 h or longer. The variations of the degree of recovery are critically discussed and put into the context of wet annealing. [ABSTRACT FROM AUTHOR]

The Two-Photon Absorption–Transient Current Technique (TPA-TCT) is a device characterisation technique that enables three-dimensional spatial resolution. Laser light in the quadratic absorption regime is employed to generate excess charge carriers only in a small volume around the focal spot. The drift of the excess charge carriers is studied to obtain information about the device under test. Neutron-, proton-, and gamma-irradiated p-type pad silicon detectors up to equivalent fluences of about 7 × 1015  n eq / c m 2 and a dose of 186   M r a d are investigated to study irradiation-induced effects on the TPA-TCT. Neutron and proton irradiation lead to additional linear absorption, which does not occur in gamma-irradiated detectors. The additional absorption is related to cluster damage, and the absorption scales according to the non-ionising energy loss. The influence of irradiation on the two-photon absorption coefficient is investigated, as well as potential laser beam depletion by the irradiation-induced linear absorption. Further, the electric field in neutron- and proton-irradiated pad detectors at an equivalent fluence of about 7 × 1015  n eq / c m 2 is investigated, where the space charge of the proton-irradiated devices appears inverted compared to the neutron-irradiated device. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive overview of the Nobel Prizes in Chemistry related to computational chemistry. It explores the history and development of the field, highlighting the contributions of notable scientists and their groundbreaking work in areas such as chemical dynamics, molecular structure, and electronic structure calculations. The article also discusses the Nobel Prizes awarded in specific years, recognizing the achievements of laureates and their significant research contributions. It acknowledges the underrepresentation of women in Nobel Prizes and reflects on the author's personal experiences and hopes for the future of computational chemistry. [Extracted from the article]

Irradiation of CeO 2 with heavy ions is commonly used to accelerate the evaluation of the irradiation performance of UO 2 nuclear fuel. However, the differences in damage rates between ions and neutrons have led to doubts about this method, making it especially important to study the dose rate effect. Here, two kinds of dose rates were used to in-situ irradiate CeO 2 using 400 keV Kr+ at 550 °C and 700 °C to study the dose rate effect on loop characteristics. High dose rate (HR) led to low-density and small-sized dislocation loops compared to low dose rate (LR), which was attributed to the initial high concentration of oxygen vacancies and enhanced recombination of point defects. HR was found to promote the direct nucleation of perfect dislocation loops (PDLs), while under LR irradiation, the PDLs tended to be formed by the transformation of Frank dislocation loops (FDLs) through a typical unfaulting. At a same dose, the proportion of PDL under the HR condition was much higher than that under the LR condition. Temperature greatly affected the loop characteristics. High temperature caused large-sized and small dense loops, as well as high PDL proportion. Moreover, the newly nucleated PDL tended to be close to the pre-existing PDLs and had the same Burgers vector as the adjacent PDL under HR irradiation at 700 °C. Current results provide underlying insights for assessing the effect of dose rate on irradiation-induced loop evolution and a reference for understanding the dose rate effect. [ABSTRACT FROM AUTHOR]

The neutron activation of stable isotopes in environmental matrices, such as soil and groundwater, is a critical aspect of assessing the impact of radionuclide production facilities on the surrounding ecosystem. The envisioned Low-Energy Radioactive Ion Beams (LERIB) facility at the iThemba LABS, South Africa is anticipated to generate significant sources of ionising radiation. The study investigated the possible repercussions of neutron irradiation stemming from the facility, focusing on the activation of stable isotopic compositions in the environment. The investigation employed a combination of experimental and analytical techniques to characterize the neutron activation products in soil and groundwater samples collected from the vicinity. Samples were collected from designated areas for background radiological measurements and were irradiated with neutrons for a period of 1 h. The induced radioactivity measured by the High Purity Germanium detector included 24Na, 22Na, 54Mn, 52Mn, and 46Sc. The application of Darcy’s law for groundwater velocity suggests that radionuclides in groundwater will migrate at an average flow velocity of 0.8 m/day. The isotopes with longer half-lives have count rates at background concentrations; therefore, environmental impacts on the site and surrounding communities might be minimal. [ABSTRACT FROM AUTHOR]

Fuel retention in plasma-facing components (PFCs) is a critical issue in future nuclear fusion reactors operating with Deuterium-Tritium (DT) regarding nuclear safety and fulfillment of the T cycle. However, during DT plasma operation, highly energetic neutrons will induce damage in the lattice of W PFCs causing enhanced fuel retention in defects or traps. Laser-Induced Breakdown Spectroscopy (LIBS) is a potential tool to monitor the T-content in situ in PFCs of future nuclear fusion devices. This article presents an ex situ study on pre-damaged W material after D plasma exposure to qualify the method and mimic conditions expected in a reactor. ITER grade W samples were displacement-damaged by 10.8 MeV W ions to a damage dose of 0.23 dpa and exposed to low temperature deuterium plasma at low energy in PlaQ. The resulting deuterium concentration was analyzed by using 3He Nuclear Reaction Analysis (depth resolution of ≈ 150 nm) as a well-established method, and LIBS (picosecond laser pulses, depth resolution of 15 nm). The sample with the highest deuterium concentration showed a deuterium-rich zone up to a depth of 1.13 μm using both techniques. This is close to the expected W ion-induced damage depth of ≈ 1 μm. The results imply that LIBS as an in situ technique for tritium monitoring could be a viable option for a reactor. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-performance structural materials (HPSMs) are needed for the successful and safe design of fission and fusion reactors. Their operation is associated with unprecedented fluxes of high-energy neutrons and thermomechanical loadings. In fission reactors, HPSMs are used, e.g., for fuel claddings, core internal structural components and reactor pressure vessels. Even stronger requirements are expected for fourth-generation supercritical water fission reactors, with a particular focus on the HPSM's corrosion resistance. The first wall and blanket structural materials in fusion reactors are subjected not only to high energy neutron irradiation, but also to strong mechanical, heat and electromagnetic loadings. This paper presents a historical and state-of-the-art summary focused on the properties and application potential of irradiation-resistant alloys predominantly strengthened by an oxide dispersion. These alloys are categorized according to their matrix as ferritic, ferritic–martensitic and austenitic. Low void swelling, high-temperature He embrittlement, thermal and irradiation hardening and creep are typical phenomena most usually studied in ferritic and ferritic martensitic oxide dispersion strengthened (ODS) alloys. In contrast, austenitic ODS alloys exhibit an increased corrosion and oxidation resistance and a higher creep resistance at elevated temperatures. This is why the advantages and drawbacks of each matrix-type ODS are discussed in this paper. [ABSTRACT FROM AUTHOR]

Microalgae are considered to be more useful and effective to use in biomass production than other photosynthesis organisms. However, microalgae need to be altered to acquire more desirable traits for the relevant purpose. Although neutron radiation is known to induce DNA mutations, there have been few studies on its application to microalgae, and the optimal relationship between irradiation intensity and mutation occurrence has not been established. In this study, using the unicellular red alga Cyanidioschyzon merolae as a model, we analyzed the relationship between the absorbed dose of two types of neutrons, high-energy (above 1 MeV) and thermal (around 25 meV) neutrons, and mutation occurrence while monitoring mutations in URA5.3 gene encoding UMP synthase. As a result, the highest mutational occurrence was observed when the cells were irradiated with 20 Gy of high-energy neutrons and 13 Gy of thermal neutrons. Using these optimal neutron irradiation conditions, we next attempted to improve the lipid accumulation of Euglena gracilis, which is a candidate strain for biofuel feedstock production. As a result, we obtained several strains with a maximum 1.3-fold increase in lipid accumulation compared with the wild-type. These results indicate that microalgae breeding by neutron irradiation is effective. [ABSTRACT FROM AUTHOR]

Background: Cyclotron‐based proton therapy systems utilize the highest proton energies to achieve an ultra‐high dose rate (UHDR) for FLASH radiotherapy. The deep‐penetrating range associated with this high energy can be modulated by inserting a uniform plate of proton‐stopping material, known as a range shifter, in the beam path at the nozzle to bring the Bragg peak within the target while ensuring high proton transport efficiency for UHDR. Aluminum has been recently proposed as a range shifter material mainly due to its high compactness and its mechanical properties. A possible drawback lies in the fact that aluminum has a larger cross‐section of producing secondary neutrons compared to conventional plastic range shifters. Accordingly, an increase in secondary neutron contamination was expected during the delivery of range‐modulated FLASH proton therapy, potentially heightening neutron‐induced carcinogenic risks to the patient. Purpose: We conducted neutron dosimetry using simulations and measurements to evaluate excess dose due to neutron exposure during UHDR proton irradiation with aluminum range shifters compared to plastic range shifters. Methods: Monte Carlo simulations in TOPAS were performed to investigate the secondary neutron production characteristics with aluminum range shifter during 225 MeV single‐spot proton irradiation. The computational results were validated against measurements with a pair of ionization chambers in an out‐of‐field region (≤$\le$ 30 cm) and with a Proton Recoil Scintillator‐Los Alamos rem meter in a far‐out‐of‐field region (0.5–2.5 m). The assessments were repeated with solid water slabs as a surrogate for the conventional range shifter material to evaluate the impact of aluminum on neutron yield. The results were compared with the International Electrotechnical Commission (IEC) standards to evaluate the clinical acceptance of the secondary neutron yield. Results: For a range modulation up to 26 cm in water, the maximum simulated and measured values of out‐of‐field secondary neutron dose equivalent per therapeutic dose with aluminum range shifter were found to be (0.57±0.02)mSv/Gy$(0.57\pm 0.02)\ \text{mSv/Gy}$ and (0.46±0.04)mSv/Gy$(0.46\pm 0.04)\ \text{mSv/Gy}$, respectively, overall higher than the solid water cases (simulation: (0.332±0.003)mSv/Gy$(0.332\pm 0.003)\ \text{mSv/Gy}$; measurement: (0.33±0.03)mSv/Gy$(0.33\pm 0.03)\ \text{mSv/Gy}$). The maximum far out‐of‐field secondary neutron dose equivalent was found to be (8.8±0.5$8.8 \pm 0.5$) μSv/Gy$\umu {\rm Sv/Gy}$ and (1.62±0.02$1.62 \pm 0.02$) μSv/Gy$\umu {\rm Sv/Gy}$ for the simulations and rem meter measurements, respectively, also higher than the solid water counterparts (simulation: (3.3±0.3$3.3 \pm 0.3$) μSv/Gy$\umu {\rm Sv/Gy}$; measurement: (0.63±0.03$0.63 \pm 0.03$) μSv/Gy$\umu {\rm Sv/Gy}$). Conclusions: We conducted simulations and measurements of secondary neutron production under proton irradiation at FLASH energy with range shifters. We found that the secondary neutron yield increased when using aluminum range shifters compared to conventional materials while remaining well below the non‐primary radiation limit constrained by the IEC regulations. [ABSTRACT FROM AUTHOR]

The study reports the significance of carbon presence in affecting void nucleation in Fe. Without carbon, void nucleation rates decrease gradually at high temperatures but remain significantly high and almost saturated at low temperatures. With carbon present, even at 1 atomic parts per million, void nucleation rates show a low-temperature cutoff. With higher carbon levels, the nucleation temperature window becomes narrower, the maximum nucleation rate becomes lower, and the temperature of maximum void nucleation shifts to a higher temperature. Fundamentally, this is caused by the change in effective vacancy diffusivity due to the formation of carbon-vacancy complexes. The high sensitivity of void nucleation to carbon comes from the high sensitivity of void nucleation to the vacancy arrival rate in a void. The void nucleation is calculated by first obtaining the effective vacancy diffusivity considering the carbon effect, then calculating the defect concentration and defect flux change considering both carbon effects and pre-existing dislocations, and finally calculating the void nucleation rate based on the recently corrected homogeneous void nucleation theory. The study is important not only in the fundamental understanding of impurity effects in ion/neutron irradiation but also in alloy engineering for judiciously introducing impurities to increase swelling resistance, as well as in the development of simulation and modeling methodologies applicable to other metals. [ABSTRACT FROM AUTHOR]

Exposure of metals to neutron irradiation results in an increase in the yield strength and a significant loss of ductility. Irradiation hardening is also closely related to the fracture toughness temperature shift or the ductile-to-brittle transition temperature (DBTT) shift in alloys with a body-centered cubic (bcc) crystal structure. Ion irradiation is an indispensable tool in the study of the radiation effects of materials for nuclear energy systems. Due to the shallow damage depth in ion-irradiated materials, the nanoindentation test is the most commonly used method for characterizing the changes in mechanical properties after ion irradiation. Issues that affect the analysis of irradiation hardening may arise due to changes in the surface morphology and mechanical properties, as well as the inherent complexities in nanoscale indentation. These issues, including changes in surface roughness, carbon contamination, the pile-up effect, and the indentation size effect, with corresponding measures, were reviewed. Modeling using the crystal plasticity finite element method of the nanoindentation of ion-irradiated materials was also reviewed. The challenges in extending the nanoindentation test to high temperatures and to multiscale simulation were addressed. [ABSTRACT FROM AUTHOR]

Studying temperature effects on defect behaviors during thermal annealing is significant for understanding the performance degradation and recovery of semiconductor devices under irradiation. We systematically studied temperature effects on annealing crucial deep-level defects in neutron-irradiated silicon, by developing a multiscale modeling approach. The temperature-dependent concentrations and electron occupation ratios of crucial defects of divacancies (V2) and tri-vacancies (V3) were given for dynamic and post-irradiation annealing. Besides the common direct dissociation, we found a new approach to eliminating V2 and V3 by their recombination with interstitials dissociated from interstitial-relative defects at relatively low temperatures. To effectively eliminate V2 and V3 by post-irradiation annealing, we further determined the activation energies of 1.98eV and 1.71eV for V2 and V3, respectively. We also found that, within the operation temperature range of devices, the higher the temperature, the better the radiation resistance. It is thus recommended that the optimal temperature of post-irradiation annealing for device performance recovery is near 600K. [ABSTRACT FROM AUTHOR]

We developed a Zr two-photon resonance ionization scheme with a high useful yield of 6.3(5)%. This scheme utilizes the known intermediate energy level at 26443.88 cm−1 and a newly characterized Rydberg level at 53490.79(26) cm−1. Both the first (378.16 nm) and second (369.727 nm) transition wavelengths are accessible by frequency-doubled titanium:Sapphire lasers. We utilize the new scheme to analyze the isotopics of Zr, a fission product, in micrometer-sized spent nuclear fuel samples to understand their irradiation history. This includes the dependence on burnup and radial location within a fuel pellet. Resonance ionization mass spectrometry was used to obtain almost isobar-free Zr isotopic ratios from seven samples. The measured isotopic ratios from the spent nuclear fuel show a strong dependence on radial position within the fuel pellet while the effect of average pellet burnup was much less pronounced. All Zr isotopic ratios systematically change from the pellet center to the pellet edge, where isotopic values are close to those expected from 235U fission and 239Pu fission, respectively. Using Zr isotopics, we demonstrate a potential method to distinguish between samples derived from the edge or center of a fuel element of unknown pedigree, which strongly impacts the interpretation of a sample's irradiation history as the neutron fields are different between these locations. [ABSTRACT FROM AUTHOR]

In boron neutron capture therapy (BNCT), boron drugs should exhibit high intratumoral boron concentrations during neutron irradiation, while being cleared from the blood and normal organs. However, it is usually challenging to achieve such tumor accumulation and quick clearance simultaneously in a temporally controlled manner. Here, we developed a polymer-drug conjugate that can actively control the clearance of the drugs from the blood. This polymer-drug conjugate is based on a biocompatible polymer that passively accumulates in tumors. Its side chains were conjugated with the low-molecular-weight boron drugs, which are immediately excreted by the kidneys, via photolabile linkers. In a murine subcutaneous tumor model, the polymer-drug conjugate could accumulate in the tumor with the high boron concentration ratio of the tumor to the surrounding normal tissue (∼10) after intravenous injection while a considerable amount remained in the bloodstream as well. Photoirradiation to blood vessels through the skin surface cleaved the linker to release the boron drug in the blood, allowing for its rapid clearance from the bloodstream. Meanwhile, the boron concentration in the tumor which was not photoirradiated could be maintained high, permitting strong BNCT effects. In clinical BNCT, the dose of thermal neutrons to solid tumors is determined by the maximum radiation exposure to normal organs. Thus, our polymer-drug conjugate may enable us to increase the therapeutic radiation dose to tumors in such a practical situation. [Display omitted] • Pharmacokinetics was actively controlled in a light-responsive manner. • Our system could achieve the high tumor accumulation and T/B ratio simultaneously. • The active control of pharmacokinetics augmented BNCT effects. [ABSTRACT FROM AUTHOR]

KAlpakkam MINI reactor (KAMINI) is a 233U fuelled research reactor has various neutron irradiation locations for experimental purposes. The pit at the south beam end of KAMINI reactor is being extensively utilised for neutron attenuation experiments in prospective shielding materials as well as for neutron radiography. During reactor operation, it will be closed by a movable shield. A vault door is located above the shield and the movable shield is used to attenuate streaming neutrons and gamma-rays during reactor operation. Even with the shield, there exists significant dose because of streaming neutrons and gamma rays. Its variation depends on the power of the reactor. The neutron and gamma dose rates close to the south beam vault door have recently been found to be 275–300 μSv/h and 175–200 μSv/h, respectively, when the reactor is operating at 10 kW. In order to characterise the streaming neutron spectra of vault door place for the first time, measurements are done using the Nested Neutron Spectrometer. Along with the neutron flux, neutron mean energy and ambient dose-equivalent rate are also measured and compared with earlier measurements carried out inside the south beam pit. It is observed that the presence of paraffin shield reduces the neutron average energy from 370 to 178 keV. Apart from energy reduction, 10 kW normalised neutron flux of south beam pit is also attenuated by the shield by 25 000 times and it is found that the neutron spectrum of the measured location is also more thermalized. Neutron reference data of the location are generated. [ABSTRACT FROM AUTHOR]

Herein we report the method to tailor the band gap and UV absorption of polyvinyl alcohol (PVA)/graphene oxide (GO)‐silver (Ag)/glutaraldehyde (GA) hybrid polymer nanocomposites. The modifications brought by neutron irradiation to the optical and dielectric characteristics enabled the band gap and UV absorption‐tailored polymer nanocomposites to be obtained. Neutron‐irradiated samples, compared with their unirradiated counterparts, exhibit a reduction in transmittance to 78%, rendering them opaque to UV–visible light after irradiation. The energy band gap decreases from 5.25 to 4.09 eV upon irradiation. Furthermore, upon neutron‐irradiation the relaxation time increases from 7.63 × 10−4 to 0.02 s which is evident by the shift in electric modulus imaginary part (M") peak to a lower frequency region, indicating an increase in relaxation time. The Cole–Cole plot for irradiated samples demonstrates lower fitting parameter (α) values of the modified Havriliak–Negami function, indicating a departure from pure capacitor‐like behavior. The neutron irradiation leads to a decrease in conductivity from 44.6 × 10−7 to 0.09 × 10−7 S/cm. [ABSTRACT FROM AUTHOR]

In the next decade, the International Commission on Radiological Protection (ICRP) will issue the next set of general recommendations, for which evaluation of relative biological effectiveness (RBE) for various types of tissue reactions would be needed. ICRP has recently classified diseases of the circulatory system (DCS) as a tissue reaction, but has not recommended RBE for DCS. We therefore evaluated the mean and uncertainty of RBE for DCS by applying a microdosimetric kinetic model specialized for RBE estimation of tissue reactions. For this purpose, we analyzed several RBE data for DCS determined by past animal experiments and evaluated the radius of the subnuclear domain best fit to each experiment as a single free parameter included in the model. Our analysis suggested that RBE for DCS tends to be lower than that for skin reactions, and their difference was borderline significant due to large variances of the evaluated parameters. We also found that RBE for DCS following mono-energetic neutron irradiation of the human body is much lower than that for skin reactions, particularly at the thermal energy and around 1 MeV. This tendency is considered attributable not only to the intrinsic difference of neutron RBE between skin reactions and DCS but also to the difference in the contributions of secondary γ-rays to the total absorbed doses between their target organs. These findings will help determine RBE by ICRP for preventing tissue reactions. [ABSTRACT FROM AUTHOR]

Radiation-induced property changes in materials originate from the energy transfer from an incoming particle to the existing lattice, displacing atoms. The displaced atoms can cause the formation of extended defects including dislocation loops, voids, or precipitates. The non-equilibrium defects created during damage events determine the extent of these larger defects and are a function of dose rate, material, and temperature. However, these defects are transient and can only be probed indirectly. This work presents direct experimental measurements and evidence of irradiated non-equilibrium vacancy formation, where in situ positron annihilation spectroscopy was used to prove the generation of non-equilibrium defects in silicon. [ABSTRACT FROM AUTHOR]

ITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called ' Pr eparation of I TER O peration' (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16–21 October 2023) London, UK [www.iaea.org/events/fec2023]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium–tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc). [ABSTRACT FROM AUTHOR]

The Spherical Tokamak for Energy Production (STEP) requires high-field magnet designs and has therefore adopted the REBCO-based high-temperature superconductor (HTS) as its current carrier. The HTS enables the toroidal field (TF) coils to be remountable, which unlocks STEP's vertical maintenance approach; however, remountable joints, approximately 18 GJ of stored energy and limited space down the centre of a spherical tokamak, make the TF coils the most challenging. STEP has pursued a passive approach to TF coil quench protection in order to limit coil terminal voltage. Initial results suggest that a solution may rely on tuning internal coil resistance coupled with actively powered heaters. The pre-conceptual inter-coil structure demonstrates acceptable stresses and deflections under steady-state operating conditions and preliminary fault scenarios, and loads are distributed to limit the tensile force on the TF centre rod. Finally, the HTS must operate reliably in a high radiation environment and endure high neutron fluences, ensuring commercially relevant magnet lifetimes. Initial experiments indicate that instantaneous gamma irradiation of HTS has no negative impact on current carrying capacity. Experimental programmes are underway to cold irradiate HTS to fusion-relevant fluences and to develop a method of assuring tape irradiation tolerance using oxygen ions as an analogue for neutrons. This article is part of the theme issue 'Delivering Fusion Energy – The Spherical Tokamak for Energy Production (STEP)'. [ABSTRACT FROM AUTHOR]

We present a first-principles-based electron-temperature model that can be used in atomistic calculations. The electron–phonon coupling coefficient in the model is derived from the density of states as a function of electron temperature, and the thermal conductivity of tungsten from our model shows significant improvement over the baseline atomistic calculations in which only ion-thermal contribution to the thermal conductivity is available. The correction to the thermal conductivity also changes damage cascades as cascades cool down more rapidly within our model. The mobility of defects is consequently reduced, leaving more residual damage than the predictions without an electron-temperature model. [ABSTRACT FROM AUTHOR]

Studies of the radiation tolerance and electrical behavior of gallium nitride (GaN) based devices are important for the next generation of high-power and high-voltage electronics that may be subjected to harsh environments such as nuclear reactor and fusion facilities, particle accelerators, and post-denotation environments. In this work, we study the behavior of Ga-polar and N-polar GaN Schottky diodes before and after exposure to fast and thermal + fast neutrons. Temperature-dependent current–voltage (I–V) and circular transmission line method (CTLM) measurements were used to study the electrical characteristics. A strong reduction in reverse leakage current and an increase in differential resistance in forward bias were observed after neutron irradiation. Thermionic emission (TE), Frenkel–Poole (FP) emission, and Fowler–Nordheim (FN) tunneling models were used to explain the forward and reverse I–V characteristics pre- and post-irradiation. The study confirms that Ga-polar and N-polar GaN Schottky diodes exhibit different electrical responses to fast and thermal neutron irradiations. The reverse bias characteristics of N-polar diodes are less affected after the fast neutron irradiation compared to Ga-polar diodes, while in the forward bias region, the electrical behavior after fast and thermal neutron irradiations is similar in Ga-polar and N-polar diodes. The results indicate that the role of orientation should be considered in the design of GaN-based radiation-tolerant electronics. [ABSTRACT FROM AUTHOR]

Simple Summary: Erect leaves are one of the important phenotypes for plants to adapt to dense planting. This study obtained the erect leaf mutant mths29 through fast neutron irradiation and directional breeding. Dynamic observation of lamina joint development in the mutant and its genetic parent Heng S29 revealed an extreme phenotype during the booting stage, characterized by the complete absence of lamina joint on the inverted second leaves and flag leaves, resulting in a close adhesion of the leaf blade to the stem and the formation of an erect leaf phenotype. Through map-based cloning, the erect leaf QTL was localized within a physical interval of 1.03 Mb on chromosome 5A, and four potential candidate genes were predicted. Here, we demonstrate that mths29 represents a novel genetic resource for erect leaf traits in wheat. This study contributes to a better understanding of lamina joint development in graminaceous and aids in shaping plant architecture for denser planting. The erect leaf plays a crucial role in determining plant architecture, with its growth and development regulated by genetic factors. However, there has been a lack of comprehensive studies on the regulatory mechanisms governing wheat lamina joint development, thus failing to meet current breeding demands. In this study, a wheat erect leaf mutant, mths29, induced via fast neutron mutagenesis, was utilized for QTL fine mapping and investigation of lamina joint development. Genetic analysis of segregating populations derived from mths29 and Jimai22 revealed that the erect leaf trait was controlled by a dominant single gene. Using BSR sequencing and map-based cloning techniques, the QTL responsible for the erect leaf trait was mapped to a 1.03 Mb physical region on chromosome 5A. Transcriptome analysis highlighted differential expression of genes associated with cell division and proliferation, as well as several crucial transcription factors and kinases implicated in lamina joint development, particularly in the boundary cells of the preligule zone in mths29. These findings establish a solid foundation for understanding lamina joint development and hold promise for potential improvements in wheat plant architecture. [ABSTRACT FROM AUTHOR]

Activation of impurities in topazes happens due to irradiation with thermal neutrons (induced radioactivity occurs), which complicates their further handling. This leads to the need for their long cooling for safe use. The Institute of Nuclear Physics (Kazakhstan) is conducting R&D to develop a method for the effective formation of color centers in topaz during their irradiation in the WWR-K reactor. An irradiation capsule design has been developed in which optimized conditions for irradiating stones in the neutron field of the reactor are formed. The capsule uses shielding materials made of boron carbide and tantalum to cut off thermal neutrons, resulting in a reduction in induced radioactivity in topaz. The effectiveness of the irradiation capsule was tested in the core of the critical facility. As a result, thermal neutron flux is reduced by 5.7 times and the induced activity of the tantalum is reduced by 2.2 times. [ABSTRACT FROM AUTHOR]

The lifespan of core graphite under neutron irradiation in a commercial molten salt reactor (MSR) has an important influence on its economy. Flattening the fast neutron flux (≥0.05 MeV) distribution in the core is the main method to extend the graphite irradiation lifespan. In this paper, the effects of the key parameters of MSRs on fast neutron flux distribution, including volume fraction (VF) of fuel salt, pitch of hexagonal fuel assembly, core zoning, and layout of control rod assemblies, were studied. The fast neutron flux distribution in a regular hexagon fuel assembly was first analyzed by varying VF and pitch. It was demonstrated that changing VF is more effective in reducing the fast neutron flux in both global and local graphite blocks. Flattening the fast neutron flux distribution of a commercial MSR core was then carried out by zoning the core into two regions under different VFs. Considering both the fast neutron flux distribution and burnup depth, an optimized core was obtained. The fast neutron flux distribution of the optimized core was further flattened by the rational arrangement of control rod channels. The calculation results show that the final optimized core could reduce the maximum fast neutron flux of the graphite blocks by about 30% and result in a more negative temperature reactivity coefficient, while slightly decreasing the burnup and maintaining a fully acceptable core temperature distribution. [ABSTRACT FROM AUTHOR]

Short-term mechanical testing of annular specimens made of a segment of the fuel element cladding irradiated in the BN-600 reactor up to damaging dose above 100 dpa has been performed. The specimens were compressed in the radial direction at different temperatures to plot experimental diagrams and analyze the stress-strain state. After testing, the fracture character and microstructure of the fracture surface were studied. It is shown that fracture of specimens at the microlevel occurs transgranularly, and the segments of fracture are observed along characteristic structural elements of cold deformed austenitic steel, along and transverse to packets of deformation twins. In general, fracture occurs with a strong deformation localization at different types of appeared defects. [ABSTRACT FROM AUTHOR]

Polyimides externally deployed in spacecraft or satellites extensively have various aerospace hazards, including atomic oxygen (AO) erosion, irradiation degradation, and electrostatic charge/discharge (ESC/ESD). To cope with these challenges, we fabricate a ZnO/CuNi‐polyimide composite film with augmented permanence. Using spectroscopy and microscopy techniques, we have shown that the combination of chelation and cross‐linking in the interfacial architecture leads to enhanced interfacial compatibility and mechanical robustness. Besides, due to the positive AO diffusion barrier ability of the wurtzite ZnO, our composite film shows remarkable AO resistance and a very small Ey value of 6.88 × 10−26 cm3/atom, which is merely 2.29% of that of pristine polyimide. Moreover, the well‐defined nanocrystalline state with minimal lattice swelling (0.3%–0.7%) of the Fe+‐irradiated ZnO/CuNi‐polyimide at a damaging dose of 353.4 dpa demonstrates its excellent irradiation resistance. Finally, the ZnO/CuNi‐polyimide also shows sufficient electrostatic dissipation capacity to cope with the ESC/ESD events. Our fabrication approach for composite films based on multi‐technology integration shows potential for aerospace applications and deployment. [ABSTRACT FROM AUTHOR]

Controlling the morphology of molecular assemblies formed by surfactants by photoirradiation enables the controlled release of incorporated substances, which can be applied to delivery systems for drugs and active ingredients. On the other hand, conventional photoresponsive surfactants and molecular assemblies have a slow response speed, making it difficult to control their functions at the desired time. In this review, I discuss our recent progress in the accelerated control of functions of photoresponsive molecular assemblies by using lophine dimer as a photochromic compound. The lophine dimer derivative dissociates into a pair of lophyl radicals that upon ultraviolet (UV) light irradiation, and these radical species thermally recombine although the recombination reaction is extremely slow due to the diffusion of lophyl radicals. By using the confined inner space of micelles formed by surfactants, the recombination reaction was extremely accelerated. With UV light irradiation, rapid morphological changes in micelles, formed by amphiphilic lophine dimers were observed by using in situ small-angle neutron scattering (in situ SANS) system. Moreover, the rapid controlled release of calcein as a model drug was achieved by UV light irradiation using the photoresponsive micelles. This rapid system can realize the controlled release of drugs truly at the desired time, developing an efficient and precise drug delivery system (DDS). Furthermore, it can be applied in a wide range of fields such as release control of active ingredients, efficient heat exchange control, and actuating systems. [ABSTRACT FROM AUTHOR]

Irradiation-induced formation of Cu-rich precipitates embrittles reactor pressure vessel steels. In the present work, a cluster dynamics model is used to model the precipitation of Cu-rich precipitates in Fe–Cu and Fe–Cu–Mn model alloys under neutron and electron irradiation at about 300 °C (573 K). The model includes radiation-enhanced diffusion and mobile Cu-rich clusters, which have been suggested to play important roles in Cu precipitation kinetics in Fe-based alloys. Precipitation at low temperatures is accelerated by radiation-enhanced diffusion, due to excess vacancies produced by displacement damages. Previous modeling work of thermal precipitation in Fe–Cu alloys at higher temperatures suggests that Cu clusters are mobile, and that this mobility must be accounted for to predict the observed precipitation kinetics. Here, the present work extends the mobile cluster model to treat precipitation in Fe–Cu and Fe–Cu–Mn alloys under neutron and electron irradiation. Comparison of the properly parameterized model predictions with the experimental observations shows that treating radiation-enhanced cluster mobility is necessary to predict Cu precipitation kinetics under irradiation. The developed precipitation model can reasonably describe the selected reliable experimental data. The model parameter determination for the physically based model includes extensive sensitivity studies, and suggests that the present approach still needs refinement to provide an accurate model that is fully consistent with the known microscopic measurements. [ABSTRACT FROM AUTHOR]

Today, BaFBr crystals activated by europium ions are used as detectors that store absorbed energy in metastable centers. In these materials, the image created by X-ray irradiation remains stable in the dark for long periods at room temperature. As a result, memory image plates are created, and they are extended to other types of ionizing radiation as well. Despite significant progress towards X-ray storage and readout of information, the mechanisms of these processes have not been fully identified to date, which has hindered the efficiency of this class of phosphors. In this study, using photoluminescence (PL), optical absorption (OA), Raman spectroscopy (RS), and atomic force microscopy (AFM), the luminescence of oxygen vacancy defects to BaFBr crystals irradiated with 147 MeV 84Kr and 24.5 MeV 14N ions at 300 K to fluences (1010–1014) ion/cm2 was investigated. BaFBr crystals were grown by the Shteber method on a special device. Energy-dispersive X-ray spectroscopy (EDX) analysis revealed the presence of Ba, Br, F, and O. The effect of oxygen impurities present in the studied crystals was considered. The analysis of the complex PL band, depending on the fluence and type of ions, showed the formation of three types of oxygen vacancy defects. Macrodefects (tracks) and aggregates significantly influence the luminescence of oxygen vacancy defects. The creation of hillocks and tracks in BaFBr crystals irradiated with 147 MeV 84Kr ions is shown for the first time. Raman spectra analysis confirmed that BaFBr crystals were amorphized by 147 MeV 84Kr ions due to track overlap, in contrast to samples irradiated with 24.5 MeV 14N ions. Raman and absorption spectra demonstrated the formation of hole and electron aggregate centers upon swift heavy ions irradiation. [ABSTRACT FROM AUTHOR]

Understanding the tritium breeding and release behavior of ceramic breeder is crucial for the parameter design of solid blanket in deuterium-tritium (D-T) fusion reactors. Lithium titanate (Li 2 TiO 3) is commonly considered an attractive candidate tritium breeder material. Defect types and densities formed by neutron irradiation at different energies result in diverse tritium release behaviors in Li 2 TiO 3. To understand the mechanism of high-energy neutrons on the tritium release of solid-state breeders, it is crucial to elucidate the tritium production and release behavior of Li 2 TiO 3 under 14 MeV fusion neutron irradiation. In this study, the high-intensity D-T fusion neutron source (HINEG-CAS) was employed to conduct tritium production experiments on Li 2 TiO 3 ceramic breeder samples. Tritium release experiment was also performed on irradiated Li 2 TiO 3 samples using the release system to obtain the temperature-dependent pattern of tritium release induced by fusion neutrons. The results indicated that a limited but visible amount of tritium was released at room temperature. Defect self-healing behavior at RT was seemly observed. The tritium release peak occurred at ∼673 K as the temperature increased. After continuous purging for 4 h at 1073 K, no residual tritium was observed in the irradiated sample, indicating successful collection through bubblers. The total radioactivity of released tritium amounted to 1866.4 Bq, predominantly in the form of tritiated water (HTO: 79.3%). Furthermore, the preliminary analysis of the mechanism behind tritium release has been provided as well. The investigation is conducive to the design optimization of the breeding blanket. • The tritium production and release experiments of Li 2 TiO 3 were conducted using 14 MeV fusion neutron irradiation. • A limited but clearly observable amount of tritium released at room temperature due to the defect self-healing behavior. • The peak of tritium release occurred at approximately 673 K and the primary form was identified as HTO (79.3%). • The influence of water vapor, sensitive tritium measurement method, and heating rate were essential for tritium release. [ABSTRACT FROM AUTHOR]

Purpose: Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy. Methods: 169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model. Results: The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed. Conclusions: These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers. [ABSTRACT FROM AUTHOR]

The triplet annihilator is a critical component for triplet–triplet annihilation upconversion (TTA-UC); both the photophysical properties of the annihilator and the intermolecular orientation have pivotal effects on the overall efficiency of TTA-UC. Herein, we synthesized two supramolecular annihilators A-1 and A-2 by grafting 9,10-diphenylanthracene (DPA) fragments, which have been widely used as triplet annihilators for TTA-UC, on a macrocyclic host—pillar[5]arenes. In A-1, the orientation of the two DPA units was random, while, in A-2, the two DPA units were pushed to a parallel arrangement by intramolecular hydrogen-bonding interactions. The two compounds showed very similar photophysical properties and host–guest binding affinities toward electron-deficient guests, but showed totally different TTA-UC emissions. The UC quantum yield of A-2 could be optimized to 13.7% when an alkyl ammonia chain-attaching sensitizer S-2 was used, while, for A-1, only 5.1% was achieved. Destroying the hydrogen-bonding interactions by adding MeOH to A-2 significantly decreased the UC emissions, demonstrating that the parallel orientations of the two DPA units contributed greatly to the TTA-UC emissions. These results should be beneficial for annihilator designs and provide a new promising strategy for enhancing TTA-UC emissions. [ABSTRACT FROM AUTHOR]

The degradation properties of Indium phosphide hetero-junction bipolar transistors (InP HBTs) under proton irradiation are studied and modelled using a compact model for pre-irradiation, post-irradiation, and post-annealing. The variation rates of the model parameters, such as the base–emitter saturation current (ISE) and ideality factor in the ideal region (NE) in the forward Gummel characteristics, the zero-biased capacitance (Cje) and the grading factor (Mjer) in the BE junction capacitance, and the transit time parameter in the base region (Tfb), are analysed to delve into the degradation mechanism induced by proton irradiation. The displacement damage, induced by proton irradiation in the space charge region of the base–emitter junction and in the quasi-neutral bulk base region, is found to be responsible for the decrease in current gain and cut-off frequency. After annealing, the variation rates of the parameters decrease significantly compared to post-irradiation. This suggests that the recombination of unstable defects leads to a slight recovery in the degradation characteristics of InP HBTs after a period of annealing. [ABSTRACT FROM AUTHOR]

A point of study in the characterization of additive manufactured (AM) alloys is whether or not AM microstructure responds to external stimuli differently from conventionally manufactured alloys. Samples of Alloy 625, a nickel-based superalloy of interest, were produced by both additive manufacturing and conventional wrought methods. Samples of differing sizes were subjected to one of two different types of neutron fields during irradiation: fast neutron or reactor-spectrum neutron. Vickers microhardness measurements and transmission electron microscope images were used to analyze the differences between samples before and after they were subjected to the neutron fields. Results showed differing responses between the two fabrication methods. [ABSTRACT FROM AUTHOR]

Deuterium-tritium fusion reactions produce energy in the form of 14.1 MeV neutrons, and hence fusion reactor components will be exposed to high energy neutron irradiation while also being subjected to thermal, mechanical and magnetic loads. Exposure to neutron irradiation has numerous consequences, including swelling and dimensional changes, comparable in magnitude to the peak transient thermal deformations occurring in plasma-facing components. Irradiation also dynamically alters the various thermo-mechanical properties, relating temperature, stress and swelling in a strongly non-linear way. Experimental data on the effect of neutron exposure spanning the design parameter space are very sparse and this highlights the relevance of computer simulations. In this study we explore the equivalence between the body force/surface traction approach and the eigenstrain formalism for treating anisotropic irradiation-induced swelling. We find that both commercial and massively parallelised open source software for finite element method (FEM) simulations are suitable for assessing the effect of neutron exposure on the mechanically loaded reactor components. We demonstrate how two primary effects of irradiation, radiation swelling and the degradation of thermal conductivity, affect the distributions of stress and temperature in the divertor of the ITER tokamak. Significant uncertainties characterising the magnitude of swelling and models for treating it suggest that on the basis of the presently available data, only an order of magnitude estimate can be given to the stress developing in reactor components most exposed to irradiation during service. [ABSTRACT FROM AUTHOR]

This study reports on the magnetic hardening phenomenon of heavily helium ion-irradiated iron–chromium alloys. The alloys are important structural materials in next-generation nuclear reactors. In some cases, problems may arise when the magnetic properties of the materials change due to neutron irradiation. Therefore, it is necessary to understand the effects of irradiation on magnetism. Helium irradiation was conducted as a simulated irradiation, and the effect of cavity formation on magnetic properties was thoroughly investigated. High-quality single-crystal Fe-x%Cr (x = 0, 10, 20) films, with a thickness of 180–200 nm, were fabricated through ultra-high vacuum evaporation. Subsequently, irradiation of 19 dpa with 30 keV He+ ions was conducted at room temperature. X-ray diffraction measurements and electron microscopy observations confirmed significant lattice expansion and the formation of high-density cavities after irradiation. The magnetization curve of pure iron remained unchanged, while magnetic hardening was noticed in iron–chromium alloys. This phenomenon is believed to be due to the combined effect of cavity formation and changes in the atomic arrangement of chromium. [ABSTRACT FROM AUTHOR]

The tensile properties of reduced activation ferritic/martensitic (RAFM) steels are significantly influenced by neutron irradiation. Here, a mechanism-based model taking account of the typical ductile damage process of void nucleation, growth, and coalescence was used to study the temperature and irradiation effects. The elastic–plastic response of RAFM steels irradiated up to 20 dpa was investigated by applying the GTN model coupled with different work hardening models. Through a numerical study of tensile curves, the GTN parameters were identified reasonably and satisfying simulation results were obtained. A combination of Swift law and Voce law was used to define the flow behavior of irradiated RAFM steels. The deformation localization could be adjusted effectively via setting the nucleation parameter εn close to the strain where necking occurs. Because εn changed with uniform elongation, εn decreased with the testing temperature and rose with an irradiation temperature above 300 °C. The nucleation parameter fn increased with the testing temperature for RAFM steels before irradiation. For irradiated RAFM steels, fn barely changed when the irradiation temperature was below 300 °C and then it rose at a higher irradiation temperature. Meanwhile, the ultimate strength of the simulated and experimental curves showed good agreement, indicating that this method can be applied to engineering design. [ABSTRACT FROM AUTHOR]

This paper introduces a novel concept of a TRISO-fueled salt-cooled reactor (TFSCR). The core contains circulating pipes filled with molten salt carrying TRISO particles. The reactor achieves online refueling by slowly circulating the molten salt through the pipeline. The reactor utilizes the same molten salt as the coolant and graphite as the moderator. The reactor design has the characteristics of safety, economy, and nonproliferation. TRISO particles exhibit greater resistance to neutron irradiation, corrosion, oxidation, and high temperatures compared to conventional fuels. A molten salt-cooled reactor can also operate at higher temperatures, consequently enhancing power generation efficiency. Furthermore, lower operating pressures can mitigate the risk of significant damages and loss of coolant caused by accidents, thereby enhancing reactor safety. This paper presents the basic nuclear design of TFSCR under the assumptions concerning the average fuel power density, the volumetric core power density, and the core temperature. At the same time, the feasibility of online refueling and long-life operation was evaluated by fuel burnup calculation. [ABSTRACT FROM AUTHOR]

Autonomous nuclear reactor monitoring is a key aspect of the International Atomic Energy Agency's strategy to ensure nonproliferation treaty compliance. From the rise of small modular reactor technology, decentralized nuclear reactor fleets may strain the capacities of such monitoring and requires new approaches. We demonstrate the superior capabilities of a gamma detection system to monitor the criticality of a zero power nuclear reactor from beyond typical vessel boundaries, offering a powerful alternative to neutron-based systems by providing direct information on fission chain propagation. Using the case example of the research reactor CROCUS, we demonstrate how two bismuth germanate scintillators placed outside the reactor vessel can precisely observe reactor criticality using so called noise methods and provide core status information in seconds. Our results indicate a wide range of applications due to the newly gained geometric flexibility that could find use in fields beyond nuclear safety. [ABSTRACT FROM AUTHOR]

This article discusses the use of silicon carbide (SiC) as a semiconductor material for radiation detectors. SiC has several advantages over conventional materials, including a wider bandgap, higher breakdown field, and higher thermal conductivity. The article describes the fabrication of SiC detectors and their performance in detecting alpha particles, X-rays, beta particles, and neutrons. It also mentions the successful application of SiC sensors in a radiation camera for X-ray imaging and particle tracking. The article concludes that SiC shows great promise as a semiconductor material for radiation detection. [Extracted from the article]

The work investigated the sorption of no-carrier-added 177Lu isolated from neutron-irradiated 176Yb2O3, and carrier-added 177Lu obtained by irradiation of natLu2O3, by commercial and oxidized nanodiamonds (NDs) of various grades from aqueous solutions to identify among them a promising carrier for further research in the field of nuclear medicine. A promising sorbent was found: oxidized NDs of the STP grade (ox-STP); conditions for the fast sorption of lutetium with it in an amount equivalent to 1.2 GBq of no-carrier-added 177Lu were determined, which corresponds to the activity used in therapy. [ABSTRACT FROM AUTHOR]