High-purity 225Ac is essential for targeted alpha therapy (TAT), yet its supply remains critically limited because co-produced 227Ac and 226Ac cannot be removed by radiochemical purification. This work presents the conceptual design and optimization of a mass separation system for high-purity 225Ac production based on the Isotope Separation On-Line (ISOL) technique and is applicable to both online and offline scenarios. The design addresses key physical processes governing isotope separation: effusion transport, beam extraction, and dispersive mass analysis, which collectively determine system performance and inform computational optimization. A Monte Carlo effusion simulation model was developed using the Geant4 toolkit to optimize the targetion source geometry. The beamline optics were optimized through transfer-matrix calculations with genetic algorithms and validated by full particle tracking using G4beamline. From the effusion simulation, quantitative relationships between geometric parameters and transport efficiency are established. Isotope separation at the focal plane achieves a radionuclidic purity exceeding 99.99%, suppressing 227Ac contamination below 10-5, representing a three-order-of-magnitude improvement over accelerator-based production without mass separation. This work establishes a systematic approach to ISOL-based therapeutic radioisotope production.

Precise neutron spectroscopy is crucial for characterizing neutron fields and optimizing nuclear power systems. Owing to their excellent neutron-gamma discrimination, both EJ309 liquid scintillator and EJ276D plastic scintillator are well-suited for fast neutron spectra measurements. To compare their performance in neutron spectra measurement, this study employs Geant4 to construct monoenergetic neutron response matrices and generate the pulse height spectra for 252Cf and 241Am-Be neutron sources for both scintillator detectors. Building upon this, neutron spectra are unfolded using the GRAVEL iterative algorithm, with the quality of neutron spectrum (Qs) serving as the metric for evaluating unfolding accuracy. Additionally, the relationships among detection efficiency, scintillator size, and neutron energy are analyzed, along with the impact of parameter settings in the GRAVEL algorithm on the unfolding results. Results indicate that EJ309 exhibits superior stability under conventional continuous spectra, while EJ276D demonstrates enhanced performance in resolving complex radiation fields. This study provides critical data and a theoretical basis for informing scintillator selection and assessing its applicability to specific neutron sources.

The design and optimization of muon beamlines for small beam spot applications present significant computational challenges, particularly when using solenoid-based focusing systems with complex edge field interactions. This paper presents the Center-Evolving (CE) algorithm, a novel hybrid optimization strategy specifically developed for muon beamline design. The CE algorithm combines parallel local search techniques with an evolving center approach to efficiently navigate high-dimensional parameter spaces while avoiding local optima stagnation. Key innovations include automated particle selection, sector-based optimization, and modular parallel computing architecture. The algorithm has been successfully applied to design the surface muon beamline for China’s first muon station (Muon station for sciEnce, technoLOgy and inDustrY - melody), achieving direct optimization for 20 mm diameter beam spots without requiring intermediate large beam spot optimization. Results demonstrate enhanced beam intensity and optimization efficiency, with the algorithm capable of handling over 30 adjustable parameters while maintaining computational efficiency on standard desktop computers.

Chirality lies at the heart of low-energy QCD, governing the symmetry structure that shapes hadron masses and strong interaction dynamics. Among the most compelling open questions tied to chiral dynamics and spontaneous chiral symmetry breaking is the longstanding Λ polarization puzzle, in which Λ hyperons produced in unpolarized hadronic collisions exhibit a surprisingly large transverse polarization that remains theoretically unexplained. This whitepaper presents the proposal for the Hyperon-Nucleon Spectrometer (H-NS) at the High-Intensity heavy-ion Accelerator Facility (HIAF). Leveraging the high energy and high intensity of HIAF's proton and heavy-ion beams, the H-NS experiment will perform systematic studies of hyperon polarization phenomena and their underlying mechanisms in proton-proton (pp), proton-nucleus (pA), and nucleus-nucleus (AA) collisions in the fixed target mode. A wide-range beam energy scan, including proton beams from 3 GeV up to 9.3 GeV (HIAF) and up to 32 GeV (upgraded HIAF), will be conducted to examine the dependence of polarization on collision energy. The spectrometer is designed with specialized detectors capable of high-precision reconstruction of final-state baryon polarizations. Among its many interesting and important measurements, H-NS will simultaneously measure hyperon and proton spin observables to explore the polarization mechanism in hadronic interactions and the spin structure of baryons. Furthermore, the use of pA and AA collisions will enable detailed investigations of cold and hot nuclear matter effects on spin polarization. Its physics program and detector development will significantly benefit the future Electron-ion Collider in China.

A new muon spin rotation/relaxation/resonance (mu SR) spectrometer is under design dedicated for the Chinese muon source, the Muon station for sciEnce technoLOgy and in DustrY (MELODY), which will be constructed at the China Spallation Neutron Source (CSNS) Phase II upgrade. The intrinsic asymmetry, detection rate and overall figure of merit (FoM) are key performance indices for the design of mu SR spectrometers. The simulations are conducted via Geant4 toolkit, employing an idealized detector setup to analyze the kinetic energy and angular distribution of the decay positrons. The influences of various factors, including the muon beam profile, polarization, beam pipes, positron degraders, detector coverage angles and energy cuts, are systematically investigated. The simulation results are validated against theoretical expectations to ensure good accuracy. This work will provide good guidance for the placement of detector arrays and external magnets in the spectrometer construction phase.

Benefiting from excellent high-frequency characteristics and superior radiation tolerance, InP is an indispensable material for next-generation high-speed communications, widely applied in optical communication, 6G radio frequency chips, AI optical interconnection, and aerospace radiation-hardened electronics. Although ion implantation greatly promotes the performance optimization of InP-based devices, it inevitably induces lattice displacement defects that degrade device reliability. Hence, quantitative evaluation of the threshold displacement energy (TDE) and dominant defect configurations in InP is essential. Our calculations reveal that the average threshold displacement energy is 18.20 eV for In atoms and 18.94 eV for P atoms. The Ed distributions for both In and P atoms predominantly lie below 30 eV and rarely exceed 40 eV. From 150 K to 900 K, In and P have a large mass difference and exhibit distinct temperature-dependent trends. The threshold displacement energy of In decreases with increasing temperature, whereas that of P rises as temperature increases. Based on the structural analysis of Frenkel pairs formed by displaced atoms, the dominant interstitial configurations are identified. These results provide detailed insights for damage evaluation and defect structure characterization in InP, benefiting ion implantation process optimization and radiation-hardening design of InP electronic devices.

Secondary electron emission (SEE) is a crucial phenomenon in field of materials science, with significant applications in electron microscopes and electron multipliers. In this research, by utilizing a combination of standard electromagnetic physics models and customized parameters, the Geant4 framework is employed to model the SEE process, which achieves the Monte Carlo simulation of SEE yield (SEY) across various materials and surface conditions. The main processes of the modelling includes inelastic scattering, elastic scattering, and interfacial transmission, are tailored to improve the accuracy of SEE simulations. The study evaluates the impact of different parameters such as cut-off energy (Ec) and surface barrier energy loss (EL) on the simulation results. With appropriate parameters, the simulation results for MgO agree well with experimental data. By normalizing the simulation results and experimental data, the two can be better matched. In the low energy of primary electrons (Ep) range of 0 < Ep/Em < 1.5, the calculated results are consistent with the experimental results with a difference less than 0.2. Additionally, the simulations are further applied to 7 materials (Al, Si, C, MgO, Al2O3, SiO2, TiN) and 3 surface conditions (incident angle, nanofilm coatings and microstructures) as application examples. The average difference between calculated maximum SEY and measured maximal SEY is less than 10 %. This Monte Carlo model is an extensible platform for SEY calculation and can provide help in the application of SEY prediction and modulation in electronic devices involving the SEE process.

This paper investigates the total ionizing dose (TID) response of commercial low-dropout regulators (LDOs) through experiments and simulations. Co-60 gamma irradiation tests were performed on RT9013 and XC6219 LDOs at a dose rate of 50 rad(Si)/s. The results show that the output voltage decreases with increasing dose, while electrical bias and load condition accelerate degradation and reduce the failure threshold. To explain these behaviors, a bias-dependent TID simulation method is developed by combining TCAD, SPICE, and Python-based automatic netlist generation. The method incorporates the actual operating bias of internal transistors and dimensional correction. The error amplifier (EA), bandgap reference (BGR), pass transistor, and complete LDO are analyzed separately. The results show that EA degradation causes abrupt output collapse, whereas BGR degradation mainly leads to gradual reference-voltage reduction. The PMOS pass transistor exhibits weak TID sensitivity within the investigated dose range. A dual sensitivity analysis further identifies the dominant transistor-level contributors in the EA and BGR. These results provide an effective approach for understanding and predicting TID-induced degradation in CMOS LDO circuits.

Proton irradiation induced single-event transients (SETs) in CMOS image sensors (CIS) can produce bright spots and bright lines that degrade imaging performance in radiation environments. This work combines 70 MeV proton irradiation experiments (flux 2.5 & times; 108 p/(cm2 & sdot;s)) with TCAD-Geant4 simulations to systematically investigate the mechanisms and energy dependence of SETs. The experimental sample is a 130 nm 5T high-dynamic-range CIS, in which three types of bright spots and bright lines are observed. In simulation, a full 3-D 5T pixel and a 2 & times;4 micro-array are first constructed in Sentaurus TCAD to analyze proton direct ionization, secondary heavy-ion ionization, bright-spot formation, and charge collection efficiency. The TCAD model is then imported into Geant4 to establish a 220 & times;220-pixel array for simulating secondary-particle transport under 1-300 MeV proton irradiation. The simulation successfully reproduces the experimentally observed SET features: secondary ions with high deposited energy, such as Si, Al, and Mg, produce large bright spots, and single-pixel, low-output spots mainly result from proton direct ionization. Bright-spot size and occurrence probability follow Weibull-type dependence on proton energy. Bright lines are primarily induced by secondary protons, alpha particles, and deuterons, and both their track length and the number of affected pixels also exhibit Weibull-type growth. These results provide a quantitative and physically consistent understanding of proton-induced SETs in CIS.

NbOx Mott memristors have demonstrated high potential in deep space detection as well as nuclear industries. However, the devices' performance under irradiation exposure remains unexplored. In this work, we investigate the impact of atmospheric neutron irradiation on the characteristics of NbOx memristors and reveal the underlying mechanisms. Our findings indicate that neutron irradiation causes significant impacts on the electrical characteristics of the device, including higher oscillation frequencies (from ∼3 kHz to ∼5 MHz), lower threshold voltage (from 2 V to 1–1.5 V), and decreased peak to peak values (> 200 mV). This is likely due to the increased diameter size of the conductive filament caused by the shift of the concentration of oxygen vacancies within the NbOx thin film, supported by corresponding electron energy loss spectroscopy results and corroborated by simulation results. This study provides valuable insights into the effects of neutron irradiation effects on NbOx Mott memristor and its applications in artificial spiking neurons.

The Second generation heavy Ion Medical Machine (SIMM) can deliver carbon ion beams with a maximum energy of 400 MeV/u and maximum current intensity of 5 ×108 pps for cancer treatment. Radiation shielding is the most effective protection measure against the prompt radiation generated by accelerators. The FLUKA program was used to perform the radiation shielding calculations and design for SIMM. Firstly, the prompt radiation field was simulated, which indicates that the secondary neutrons are the determining factor for shielding thickness. Then, the shielding effects of different combinations were compared, and the combination of iron and concrete is selected for local shielding. Finally, the radiation shielding design was completed according to the layout of the building, the beam loss parameters and the related design standards, as well as the radiation dose rates at 58 points of interest outside the shielding met the prescribed safety criteria. The radiation shielding scheme given in this study can provide a reliable guarantee of radiation safety for SIMM.

The neutron flux monitoring (NFM) system of the fission chamber in the Experimental Advanced Superconducting Tokamak (EAST) operates in a dual-mode configuration that combines pulse counting and Campbell modes, enabling wide-range measurements across eight orders of magnitude. The accuracy of cross-calibration between these two modes is of paramount importance. Conventional calibration studies typically employ simulated signals based on idealized Gaussian amplitude distribution (GD) models, which deviate from the asymmetric response characteristics of practical detectors. To address this limitation, a parametric neutron signal generation system was developed in this study. By integrating a programmable signal source capable of outputting GD and experimentally amplitude distribution (EAD) pulse signals, the system enables a comprehensive evaluation of their respective impacts on dual-mode cross-calibration intervals and error margins. The results show that the effective calibration interval for the GD source extends from 5 & times; 104 to 5 & times; 105 cps, while that for the EAD source shifts to 2 & times; 104 to 4 & times; 105 cps. Compared with the conventional GD-based calibration approach, the EAD method reduces the cross-calibration error in converting the mean square voltage integral of neutron pulse signals collected in Campbell mode into pulse count rate by 1.07%, representing a relative reduction of 15.59%. These findings demonstrate that the EAD calibration method significantly enhances the accuracy of dual-mode calibration in the fission chamber.

Mott memristors have attracted significant attention for their applications in neuromorphic computing in deep space tasks. However, the devices’ reliability under radioactive environments remains a critical concern. In this work, we investigate the impact of proton irradiation on the performance of NbOx memristors and reveal the underlying mechanisms. Our findings indicate that proton irradiation drastically impacts the electrical characteristics of the device, such as the increased threshold voltage from 1.2 V to >2 V and higher cycle to cycle variation. This is likely due to the change in conductive filament sizes and partial surface destructions, which are supported by associated Photoluminescence (PL) Spectroscopy and atomic force microscopy (AFM) results. Interestingly, self-healing effects are observed after two weeks, possibly due to room temperature annealing effects. This study provides valuable insights into the effects of proton irradiation effects on NbOx Mott memristor and its applications in artificial spiking neurons.

The global energy transition has driven rare-earth demand beyond supply, creating an urgent need for intelligent separation processes, for which highly selective online monitoring is a key enabler of fine process control and cost-efficient operation. Ultraviolet-visible (UV-Vis) spectroscopy offers non-invasive and rapid response capabilities; however, in solvent-extraction engineering its quantitative accuracy is severely compromised by scattering-induced turbidity as well as baseline and wavelength drift. To address these challenges, this study proposes an ion-concentration diagnostic method that integrates adaptive peak-valley differencing with robust regression: dynamic local differencing is employed to suppress broadband background components, and hierarchical, element-specific modeling is implemented based on spectral characteristics (second-order correction or ridge regression). Optimization results show that, compared with the conventional single-wavelength approach, the proposed strategy substantially mitigates background interference, improving the coefficient of determination (R2) for the weak-signal element Tb from 0.98299 to 0.99971. Incorporating ridge regression further suppresses noise-induced overfitting, raising the R2 values of Dy, Pr, and Tb to above 0.999, reducing the limits of detection (LOD) to 0.01275, 0.00200, and 0.3773 g L-1, and lowering the coefficients of variation (CV) in low-concentration repeat measurements to 2.9%, 1.1%, and 9.98%, respectively. During a four-week, cross-period monitoring test, the spectral feature correlation coefficient consistently remained at an exceptionally high level (r > 0.9999). Overall, the proposed diagnostic method demonstrates strong robustness for micro-level detection and long-term operation, providing a reference technical method for online concentration diagnosis and performance optimization in rare-earth solvent-extraction processes.

To overcome the complexity and challenges of transient gamma irradiation experiments, this article adopted pulsed lasers to simulate the transient dose rate effect (TDRE) on commercial off-the-shelf (COTS) field-programmable gate array (FPGA), taking advantage of good stability, low interference, high efficiency, and low cost. Three test programs were designed for the Virtex-5 XC5VSX95T FPGA, including one program used in previous transient gamma irradiation experiments. Laser experiments involved a wide energy range and recorded failure features of the device under test (DUT) and photocurrents on the power supplies. By comparing the results with transient irradiation experiments, it was demonstrated that pulsed lasers can be used to effectively simulate FPGA's TDRE, showing consistent effect characteristics. In addition, the sensitivity of the internal clock and logic resources of the FPGA was analyzed, finding that delay-locked loops (DLLs) have a high sensitivity and disturbances in the logic resources could propagate. There are multiple factors affecting the internal sensitivities. Furthermore, like transient gamma rays, high-intensity pulsed lasers would also induce dynamic reconfiguration of the FPGA, which was analyzed specifically. These research findings are important supplements to studying FPGA's TDRE and also demonstrate significant prospect of using pulsed lasers to simulate the TDRE in very large-scale integrated (VLSI) circuits.

Electronic equipment applied in the complex space environment may have combined damage under the independent conditions of temperatures, radiation effects and operating modes. The aim of this study is to evaluate the laser-induced single event transients (SETs) on dependence of the pre-irradiation elevated temperatures, accumulated total dose, bias conditions and laser energy for different SiGe processes. The experimental results show that the SETs response of SiGe HBTs are closely associated with the device structure and HBT designs. TCAD simulations are combined to demonstrate that KT9041 SiGe HBTs are more sensitive to SETs than IBM43RF0100.

The induced radioactivity of cooling water is a critical component of accelerator radiation protection. The High-Intensity heavy-ion Accelerator Facility (HIAF), characterized by high particle energy and large beam current, generates strong induced radioactivity in its cooling water, which may pose radiation hazards to personnel and the environment. Therefore, it is necessary to investigate the induced radioactivity of HIAF's cooling water. In this work, a systematic simulation study was performed using the Monte Carlo package FLUKA, combined with the beam loss parameters and the cooling water system design. First, the results indicate that the main radioactive nuclides produced in the cooling water are 15O, 3H, 11C, 7Be and 13N. Second, after 30 years of continuous operation, the radionuclide activity concentration in the cooling water of HIAF's six water stations ranges from 3.29 Bq/g to 9.33× 102 Bq/g, and total activity spans from 5.76× 107 Bq to 1.73× 1010 Bq. In addition, considering the nuclides with γ and β+ radiation, the dose rates around the cooling water pipes of each water station were simulated. At a distance of 30 cm from the pipes, dose rates range from 0.17 μSv/h to 21.67 μSv/h. These rates can be significantly reduced by a 1 cm thick lead shield or 1 h of decay. Finally, the decay tanks were designed to ensure that the radioactive wastewater containing 3H and 7Be could be safely discharged in accordance with relevant standard. This research provides essential data for the radiation safety management of HIAF and serves as a reference for the related studies on similar accelerator facilities.

Aiming at the limited prior knowledge from the pulsed neutron radiation field, a new method for neutron/ gamma pulse shape discrimination (PSD) is proposed based on the theory of Voiceprint Identification (VI). This method primarily involves five steps: feature extraction of Mel-Frequency Cepstral Coefficients, training of a universal background model (UBM), adaptive training of neutron/gamma Gaussian Mixture Model (GMM), model verification, and application. For 1000 small sample training sets provided by commercial organic scintillator detectors, the accuracy of this method was proven to be as high as 99 %, comparable to the classical charge integral method. The waveforms obtained under varying experimental conditions were used for unsupervised discrimination. The results demonstrate that this method offers high accuracy, robust feature extraction capabilities, strong generalization abilities, exceptional adaptability, and rapid computational speed.

Double data rate 5 synchronous dynamic random access memory (DDR5 SDRAM), as the latest generation in its family, is an outstanding candidate for future space applications, highlighting the importance of considering its radiation performance. In this article, we investigated the proton-induced radiation effects on DDR5 dual-inline-memory-modules (DIMMs) for the first time. Consumer-grade DDR5 modules were tested, taking into account several factors, including proton energy, module vendors, and the specific power management unit (PMU) on DDR5. The results provided the single-event effect (SEE) cross section (CS) curve as a function of proton energy and uncovered the sensitivity of different vendors and the PMU. In addition, comparison tests between server-grade DDR4 and DDR5 modules were conducted to study the impacts of different generations, external error correction code (ECC) cases, and accumulated effects. Fault injection simulations were also conducted to identify potential causes for the observed patterns in the experiments with the existence of on-die ECC.

The Monte Carlo code, FLUKA, was used to com pute the in duced ra dio ac tiv ity in treat ment room for pro ton ther apy, car bon ion ther apy, and bo ron neu tron cap ture ther apy. For mod el ing ac tiv ity buildup, a pe ri odic ir ra di a tion ac tiv ity buildup ap proach was em ployed. Re sults show that air ac ti va tion lev els from all three ther a pies are ex tremely low. In pa tients, pro ton/car bon ion ther apy mainly gen er ates short-lived iso topes like 15O, with dose rates at 1 m ther apy, how ever, pro duces lon ger-lived iso topes (24N, 38Cl), lead ing to el e vated dose rates for sev eral hours and re quir ing post-treat ment con trol mea sures. No ta bly, con crete ac ti va tion di verges sig nif i cantly: for pro ton/car bon ion ther apy, the in duced ac tiv ity re mains low (similar to 107 Bq), pos ing min i mal risks to ra di a tion ex po sure or waste dis posal. Bo ron neu tron cap ture ther apy, by con trast, in creases con crete ac ti va tion by two or ders of mag ni tude. Af ter one week of op er a tion, 24Na buildup causes the dose rate at the treat ment room cen ter to reach 39.5 & micro;Svh-1 (af ter 5 min ute cool ing) -15 times the con ven tional limit (2.5 & micro;Svh-1). Af ter 30 years of op er a tion and one month of shut down, the ac tiv ity of 55Fe ex ceeds the ex emp tion limit by a fac tor of 42.1. This study pro vides key guid ance for ra di a tion shield ing de sign, waste man age ment, and clin i cal pro to col op ti mi za tion for ad vanced ra dio ther apy fa cil i ties.