Betavoltaic nuclear batteries offer a promising alternative energy source that harnesses the power of beta particles emitted by radioisotopes. To satisfy the power demands of microelectromechanical systems (MEMS), 3D structures have been proposed as a potential solution. Accordingly, this paper introduces a novel 3D ⁶³Ni-SiC-based P⁺PNN⁺ structure with a multi-groove design, avoiding the need for PN junctions on the inner surface, and thus reducing leakage current and power losses. Monte Carlo simulations were performed considering the fully coupled physical model to extend the electron–hole pair generation rate to a 3D structure, enabling the efficient design and development of betavoltaic batteries with complex 3D structures. As a result, the proposed model produces the significantly higher maximum output power density of 19.74 µW/cm² and corresponding short-circuit current, open-circuit voltage, and conversion efficiency of 8.57 µA/cm², 2.45 V, and 4.58%, respectively, compared with conventional planar batteries. From analysis of the carrier transport and collection characteristics using the COMSOL Multiphysics code, we provide deep insights regarding power increase, and elucidate the discrepancies between the ideal and simulated performances of betavoltaic batteries. Our work offers a promising approach for the design and optimization of high-output betavoltaic nuclear batteries with a unique 3D design, and serves as a valuable reference for future device fabrication.

The transient multiphysics models were updated in CAMPUS to evaluate the accident-tolerant fuel performance under accident conditions. CAMPUS is a fuel-performance code developed based on COMSOL. The simulated results of the UO₂-Zircaloy fuel performance under accident conditions were compared with those of the FRAPTRAN code and the experimental data to verify the correctness of the updated CAMPUS. Subsequently, multiphysics models of the UO₂-BeO fuel and composite SiC coated with Cr (SiC_f/SiC-Cr) cladding were implemented in CAMPUS. Finally, the fuel performance of the three types of fuel-cladding systems under Loss of Coolant Accident (LOCA) and Reactivity Insertion Accident (RIA) condtions were evaluated and compared, including the temperature distribution, stress distribution, pressure evolution, and cladding failure time. The results showed that the fuel temperature of the UO₂ fuel under accident conditions without pre-irradiation was lower after being combined with SiC_f/SiC-Cr cladding. Moreover, the centerline and outer surface temperatures of the UO₂-BeO fuel combined with SiC_f/SiC-Cr cladding reduced further under accident conditions. The cladding temperature increased after the combination with the SiC_f/SiC-Cr cladding under accident conditions with pre-irradiation. In addition, the use of SiC_f/SiC-Cr cladding significantly reduced the cladding hoop strain and plenum pressure.

The estimation of model parameters is an important subject in engineering. In this area of work, the prevailing approach is to estimate or calculate these as deterministic parameters. In this study, we consider the model parameters from the perspective of random variables and describe the general form of the parameter distribution inference problem. Under this framework, we propose an ensemble Bayesian method by introducing Bayesian inference and the Markov chain Monte Carlo (MCMC) method. Experiments on a finite cylindrical reactor and a 2D IAEA benchmark problem show that the proposed method converges quickly and can estimate parameters effectively, even for several correlated parameters simultaneously. Our experiments include cases of engineering software calls, demonstrating that the method can be applied to engineering, such as nuclear reactor engineering.

The complex structure and strong heterogeneity of advanced nuclear reactor systems pose challenges for high-fidelity neutron-shielding calculations. Unstructured meshes exhibit strong geometric adaptability and can overcome the deficiencies of conventionally structured meshes in complex geometry modeling. A multithreaded parallel upwind sweep algorithm for S_N transport was proposed to achieve a more accurate geometric description and improve the computational efficiency. The spatial variables were discretized using the standard discontinuous Galerkin finite-element method (DGFEM). The angular flux transmission between neighboring meshes was handled using an upwind scheme. In addition, a combination of a mesh transport sweep and angular iterations was realized using a multithreaded parallel technique. The algorithm was implemented in the 2D/3D S_N transport code ThorSNIPE, and numerical evaluations were conducted using three typical benchmark problems: IAEA, Kobayashi-3i, and VENUS-3. These numerical results indicate that the multithreaded parallel upwind sweep algorithm can achieve high computational efficiency. ThorSNIPE, with a multithreaded parallel upwind sweep algorithm, has good reliability, stability, and high efficiency, making it suitable for complex shielding calculations.

Iron is commonly used as a structural and shielding material in nuclear devices. The accuracy of its nuclear data is critical for the design of nuclear devices. The evaluation data of ⁵⁶Fe isotopes in the latest version of the CENDL-3.2 library from China was significantly updated. This new data must be tested before it can be used. To test the reliability of this data and assess the shielding effect, a shielding benchmark experiment was conducted with natural Fe spherical samples using a pulsed deuterium-tritium neutron source at the China Institute of Atomic Energy (CIAE). The leakage neutron spectra from the natural spherical iron samples with different thicknesses (4.5, 7.5, and 12 cm) were measured between 0.8-16 MeV after interacting with 14 MeV neutrons using the time-of-flight method. The simulation results were obtained by Monte Carlo simulations by employing the Fe data from the CENDL-3.2, ENDF/B-VIII.0, and JEDNL-5.0 libraries. The measured and simulated leakage neutron spectra and penetration rates were compared, demonstrating that the CENDL-3.2 library performs sufficiently overall. The simulation results of the other two libraries were underestimated for scattering at the continuum energy level.

Photonuclear reactions using a laser Compton scattering (LCS) gamma source provide a new method for producing radioisotopes for medical applications. Compared with the conventional method, this method has the advantages of a high specific activity and less heat. Initiated by the Shanghai Laser Electron Gamma Source (SLEGS), we conducted a survey of potential photonuclear reactions, γ, n, (γ, p), and (γ, γ′) whose cross-sections can be measured at SLEGS by summarizing the experimental progress. In general, the data are rare and occasionally inconsistent. Therefore, theoretical calculations are often used to evaluate the production of medical radioisotopes. Subsequently, we verified the model uncertainties of the widely used reaction code TALYS-1.96, using the experimental data of the ¹⁰⁰Moγ, n⁹⁹Mo, ⁶⁵Cuγ, n⁶⁴Cu, and ⁶⁸Zn(γ, p)⁶⁷Cu reactions.

Typically, the unambiguous determination of the quantum numbers of nuclear states is a challenging task. Recently, it has been proposed to utilize to this aim vortex photons in the MeV energy region and, potentially, this could revolutionize nuclear spectroscopy because of the new and enhanced selectivity of this probe. Moreover, nuclei may become diagnostic tools for vortex photons. Still, some open questions have to be dealt with.

From the empirical phenomena of fragment distributions in nuclear spallation reactions, semiempirical formulas named SPAGINS were constructed to predict fragment crosssections in high-energy γ-induced nuclear spallation reactions (PNSR). In constructing the SPAGINS formulas, theoretical models, including the TALYS toolkit, SPACS, and Rudstam formulas, were employed to study the general phenomenon of fragment distributions in PNSR with incident energies ranging from 100 to 1000 MeV. Considering the primary characteristics of PNSR, the SPAGINS formulas modify the EPAX and SPACS formulas and efficiently reproduce the measured data. The SPAGINS formulas provide a new and effective tool for predicting fragment production in PNSR.

Bayesian analysis was employed to constrain the Equation of State (EoS) of nuclear matter with a baryon density of up to six times the nuclear saturation density, using data from heavy-ion collisions at beam energies sNN=2−10 GeV. The resulting EoS excellently agrees with that constrained by astrophysical observations.

Information on the decay process of nuclides in the superheavy region is critical in investigating new elements beyond oganesson and the island of stability. This paper presents the application of a random forest algorithm to examine the competition among different decay modes in the superheavy region, including α decay, β^- decay, β⁺ decay, electron capture and spontaneous fission. The observed half-lives and dominant decay mode are well reproduced. The dominant decay mode of 96.9% of the nuclei beyond ²¹²Po is correctly obtained. Further, α decay is predicted to be the dominant decay mode for isotopes in new elements Z = 119-122, except for spontaneous fission in certain even–even elements owing to the increased Coulomb repulsion and odd–even effect. The predicted half-lives demonstrate the existence of a long-lived spontaneous fission island southwest of ²⁹⁸Fl caused by the competition between the fission barrier and Coulomb repulsion. A better understanding of spontaneous fission, particularly beyond ²⁸⁶Fl, is crucial in the search for new elements and the island of stability.

The simultaneous measurement of the spatial profile and spectrum of laser-accelerated protons is important for further optimization of the beam qualities and applications. We report a detailed study regarding the underlying physics and regular procedure of such a measurement through the radioactivation of a stack composed of aluminum, copper, and CR-39 plates as well as radiochromic films (RCFs). After being radioactivated, the copper plates are placed on imaging plates (IPs) to detect the positrons emitted by the reaction products through contact imaging. The spectrum and energy-dependent spatial profile of the protons are then obtained from the IPs and confirmed by the measured ones from the RCFs and CR-39 plates. We also discuss the detection range, influence of electrons, radiation safety, and spatial resolution of this measurement. Finally, insights regarding the extension of the current method to online measurements and dynamic proton imaging are also provided.

Image quality in positron emission tomography (PET) is affected by random and scattered coincidences and reconstruction protocols. In this study, we investigated the effects of scattered and random coincidences from outside the field of view (FOV) on PET image quality for different reconstruction protocols. Imaging was performed on the Discovery 690 PET/CT scanner, using experimental configurations including the NEMA phantom (a body phantom, with six spheres of different sizes) with a signal background ratio of 4:1. The NEMA phantom (phantom I) was scanned separately in a one-bed position. To simulate the effect of random and scatter coincidences from outside the FOV, six cylindrical phantoms with various diameters were added to the NEMA phantom (phantom II). The 18 emission datasets with mean intervals of 15 min were acquired (3 min/scan). The emission data were reconstructed using different techniques. The image quality parameters were evaluated by both phantoms. Variations in the signal-to-noise ratio (SNR) in a 28-mm (10-mm) sphere of phantom II were 37.9% (86.5%) for ordered-subset expectation maximization (OSEM-only), 36.8% (81.5%) for point spread function (PSF), 32.7% (80.7%) for time of flight (TOF), and 31.5% (77.8%) for OSEM + PSF + TOF, respectively, indicating that OSEM + PSF + TOF reconstruction had the lowest noise levels and lowest coefficient of variation (COV) values. Random and scatter coincidences from outside the FOV induced lower SNR, lower contrast, and higher COV values, indicating image deterioration and significantly impacting smaller sphere sizes. Amongst reconstruction protocols, OSEM + PSF + TOF and OSEM + PSF showed higher contrast values for sphere sizes of 22, 28, and 37 mm and higher contrast recovery coefficient (CRC) values for smaller sphere sizes of 10 and 13 mm.

In γ-ray imaging, localization of the γ-ray interaction in the scintillator is critical. Convolutional neural network (CNN) techniques are highly promising for improving γ-ray localization. Our study evaluated the generalization capabilities of a CNN localization model with respect to the γ-ray energy and thickness of the crystal. The model maintained a high positional linearity (PL) and spatial resolution (SR) for ray energies between 59–1460 keV. The PL at the incident surface of the detector was 0.99, and the resolution of the central incident point source ranged between 0.52–1.19 mm. In modified uniform redundant array (MURA) imaging systems using a thick crystal, the CNN γ-ray localization model significantly improved the useful field-of-view (UFOV) from 60.32% to 93.44% compared to the classical centroid localization methods. Additionally, the signal-to-noise ratio (SNR) of the reconstructed images increased from 0.95 to 5.63.

In the past decade, boron neutron capture therapy (BNCT) utilizing an accelerator-based neutron source (ABNS) designed primarily for producing epithermal neutrons has been implemented in the treatment of brain tumors and other cancers. The specifications for designing an epithermal beam are primarily based on the IAEA-TECODC-1223 report, issued in 2001 for reactor neutron sources. Based on this report, the latest perspectives and clinical requirements, we designed an ABNS capable of adjusting the average neutron beam energy. The design was based on a 2.8 MeV, 20 mA proton beam bombarding a lithium target to produce neutrons that were subsequently moderated and tuned through a tunable beam shaping assembly (BSA) which can modify the thicknesses and materials of the coin-shaped moderators, back reflectors, filters, and collimators. The simulation results demonstrated that epithermal neutron beams for deep seated tumor treatment, which were generated by utilizing magnesium fluoride with lengths ranging between 28 cm and 36 cm as the moderator, possessed a treatment depth of 5.6 cm although the neutron flux peak shifts from 4.5 keV to 1.0 keV. When utilizing a thinner moderator, a less accelerated beam power can meet the treatment requirements. However, higher powers reduced the treatment time. In contrast, employing a thick moderator can reduce the skin dose. In scenarios that required relatively low energy neutron beams, the removal of the thermal neutron filter can raise the thermal neutron flux at the beam port. And the depth of the dose rate peak could be adjusted between 0.25 cm and 2.20 cm by combining magnesium fluoride and polyethylene coins of different thicknesses. Hence, this device has a better adaptability for the treatment of superficial tumors. Overall, the tunable BSA provides greater flexibility for clinical treatment than common BSA designs that can only adjust the port size.

The corrosion behavior of 316H stainless steel (SS) in the impure and purified NaCl-KCl-MgCl₂ salt was investigated at 700 ℃. Results indicate that the main deleterious impurity induced corrosion in the impure salt was the absorbed moisture, present in the form of MgCl₂·6H₂O. 316H SS occurred severe intergranular corrosion with a corrosion depth of 130 μm for 1000 h in the impure NaCl-KCl-MgCl₂ salt. In contrast, the purification treatment of molten chloride salt by the dissolved Mg metal can remove the absorbed moisture, and the corresponding reactions were also discussed. As a result, the corrosiveness of NaCl-KCl-MgCl₂ salt is reduced significantly. 316H SS occurred slight uniform corrosion with a depth of less than 5 μm for 3000 h in the purified NaCl-KCl-MgCl₂ salt.

Machine learning-based surrogate models have significant advantages in terms of computing efficiency. In this paper, we present a pilot study on fast calibration using machine learning techniques. Technology computer-aided design (TCAD) is a powerful simulation tool for electronic devices. This simulation tool has been widely used in the research of radiation effects. However, calibration of TCAD models is time-consuming. In this study, we introduce a fast calibration approach for TCAD model calibration of metal-oxide-semiconductor field-effect transistors (MOSFETs). This approach utilized a machine learning-based surrogate model that was several orders of magnitude faster than the original TCAD simulation. The desired calibration results were obtained within several seconds. In this study, a fundamental model containing 26 parameters is introduced to represent the typical structure of a MOSFET. Classifications were developed to improve the efficiency of the training sample generation. Feature selection techniques were employed to identify important parameters. A surrogate model consisting of a classifier and a regressor was built. A calibration procedure based on the surrogate model was proposed and tested with three calibration goals. Our work demonstrates the feasibility of machine learning-based fast model calibrations for MOSFET. In addition, this study shows that these machine learning techniques learn patterns and correlations from data instead of employing domain expertise. This indicates that machine learning could be an alternative research approach to complement classical physics-based research.

This study proposes a source distribution inversion convolutional neural network (SDICNN), which is deep neural network model for the inversion of complex source distributions, to solve inversion problems involving fixed-source distributions. A function is developed to obtain the distribution information of complex source terms from radiation parameters at individual sampling points in space. The SDICNN comprises two components: a fully connected network and a convolutional neural network. The fully connected network mainly extracts the parameter measurement information from the sampling points, whereas the convolutional neural network mainly completes the fine inversion of the source-term distribution. Finally, the SDICNN obtains a high-resolution source-term distribution image. In this study, the proposed source-term inversion method is evaluated based on typical geometric scenarios. The results show that, unlike the conventional fully connected neural network, the SDICNN model can extract the two-dimensional distribution features of the source terms, and its inversion results are better. In addition, the effects of the shielding mechanism and number of sampling points on the inversion process are examined. In summary, the result of this study can facilitate the accurate assessment of dose distributions in nuclear facilities.

HFRS (HIAF FRagment separator (HFRS) will be the radioactive secondary beam separation line on High-Intensity heavy-ion Accelerator Facility (HIAF) in China. Several TPC detectors, with high count rates, are planned for particle identification and beam monitoring at HFRS. This paper presents an event-driven internal memory and synchronous readout (EDIMS) prototype ASIC chip. The aim is to provide HFRS-TPC with high-precision time and charge measurements with high count rates and a large dynamic range. The first prototype EDIMS chip integrated 16 channels and is fabricated using a 0.18-μm CMOS process. Each channel consists of a charge-sensitive amplifier, fast shaper, slow shaper, peak detect-and-hold circuit, discriminator with time-walk compensation, analog memory, and FIFO. The token ring is used for clock-synchronous readout. The chip is taped and tested.

The reconstruction of the tracks of charged particles with high precision is crucial for HEP experiments to achieve their physics goals. The BESIII drift chamber, which is used as the tracking detector of the BESIII experiment, has suffered from aging effects resulting in degraded tracking performance after operation for approximately 15 years. To preserve and enhance the tracking performance of BESIII, one of the proposals is to add one layer of a thin cylindrical CMOS pixel sensor based on state-of-the-art stitching technology between the beam pipe and the drift chamber. The improvement in the tracking performance of BESIII with such an additional pixel detector compared to that with only the existing drift chamber was studied using the modern common tracking software acts, which provides a set of detector-agnostic and highly performant tracking algorithms that have demonstrated promising performance for a few high-energy physics and nuclear physics experiments.

"A Craftsman Must Sharpen His Tools to Do His Job," said Confucius. Nuclear detecting and readout techniques are the foundation of particle physics, nuclear physics, and particle astrophysics to reveal the nature of the universe. Also, they are being increasingly used in other disciplines like nuclear power generation, life sciences, environmental sciences, medical sciences, etc. The article reviews the short history, recent development, and trend of nuclear detecting and readout techniques, covering Semiconductor Detectors, Gaseous Detectors, Scintillation Detectors, Cherenkov Detectors, Transition Radiation Detectors, and Readout Techniques. By explaining the principle and using examples, we hope to help the interested reader understand this intersection and bring exciting information to the community.

Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility has been relocated, upgraded, and given a new ID (BL02U1). It now delivers X-rays in the energy range of 6–16 keV, with a focused beam of 11.6 µm × 4.8 µm and photon flux greater than 10¹² phs/s. The high credibility and stability of the beam and good timing synchronization of the equipment significantly improve the experimental efficiency. Since June 2021, when it officially opened to users, over 4200 h of beamtime have been provided to over 200 research groups to collect data at the beamline. Its good performance and stable operation have led to the resolution of several structures based on data collected at the beamline.

A new X-ray imaging and biomedical application beamline (BL13HB) has been implemented at the Shanghai Radiation Synchrotron Facility (SSRF) as an upgrade to the old X-ray imaging and biomedical application beamline (BL13W1). This is part of the Phase II construction project of the SSRF. The BL13HB is dedicated to 2D and 3D static and dynamic X-ray imaging, with a field of view of up to 48.5 mm × 5.2 mm and spatial resolution as high as 0.8 μm. A super-bending magnet is used as the X-ray source in BL13HB, which has a maximum magnetic field of 2.293 T. The energy range of monochromatic X-ray photons from a double-multiplayer monochromator was 8-40 keV, and the white beam mode was provided on the beamline for dynamic X-ray imaging and dynamic X-ray micro-CT. While maintaining the previous experimental setup of BL13W1, new equipment was added to the beamline experimental station. The beamline is equipped with different sets of X-ray imaging detectors for several experimental methods such as micro-CT, dynamic micro-CT, and pair distribution function (PDF). The experimental station of BL13HB is designed specifically for various in situ dynamic experiments, and BL13HB has been open to users since June 2021.

Evaluating the comprehensive characteristics of extreme ultraviolet (EUV) photoresists is crucial for their application in EUV lithography, a key process in modern technology. This paper highlights the capabilities of the Shanghai Synchrotron Radiation Facility (SSRF) 08U1B beamline in advancing this field. Specifically, it demonstrates how this beamline can create fringe patterns with a 15-nm half-pitch (HF) on a resist using synchrotron-based EUV lithography (EUV-IL). This achievement is vital for evaluating EUV photoresists at the advanced 5-nm node. We provide a detailed introduction to the methods and experimental setup used at the SSRF 08U1B beamline to assess an EUV photoresist. A significant part of this research involved the fabrication of high-resolution hydrogen silsesquioxane (HSQ) mask gratings. These gratings, with an aspect ratio of approximately 3, were created using electron beam lithography (EBL) on an innovative mask framework. This framework was crucial in eliminating the impact of zeroth-order light on interference patterns. The proposed framework propose offers a new approach to mask fabrication, particularly beneficial for achromatic Talbot lithography and multicoherent-beam interference applications.

Full-field transmission X-ray microscopy (TXM) is a powerful nondestructive three-dimensional (3D) imaging method with a nanoscale spatial resolution that has been used in most synchrotron facilities worldwide. An in-house-designed TXM system was constructed at the BL18B 3D Nanoimaging beamline at the Shanghai Synchrotron Radiation Facility. The beamline operates from 5 to 14 keV and enables 20 nm spatial resolution imaging. The characterization details of the beamline are described in this paper. The performances in terms of spatial resolution, nano-CT, and nano-spectral imaging of the TXM beamline are also presented in this article.

BL10U2 is an undulator-based macromolecular crystallography (MX) beamline located at the 3.5-GeV Shanghai Synchrotron Radiation Facility. BL10U2 is specifically designed for conducting routine and bio safety level-2 (BSL-2) MX experiments utilizing high-flux tunable X-rays with energies from 7 to 18 keV, providing a beam spot size of 20 µm (horizontal) × 10 µm (vertical) at the sample point. Certification by the Shanghai Pudong Municipal Health Commission confirmed the capability to perform BSL-2 MX experiments. The beamline is currently equipped with an Eiger X 16M detector and two newly developed in-house high-precision diffractometers that can be switched to perform conventional or in situ crystal diffraction experiments. An automatic sample changer developed in-house allows fast sample exchange in less than 30s, supporting high-throughput MX experimentation and rapid crystal screening. Data collection from both the diffractometer and detector was controlled by an in-house developed data collection software (Finback) with a user-friendly interface for convenient operation. This study presents a comprehensive overview of the facilities, experimental methods, and performance characteristics of the BL10U2 beamline.