The response of an anti-Compton phoswich detector to gamma rays was investigated using Monte-Carlo method, and the pulses from different crystal cases, including gamma deposition only in the LaBr3(Ce) or CsI(Tl) crystal and coincidence in both crystals, were analyzed. A novel pulse discrimination method for gamma deposition events based on wavelet transform analysis, called SSD (Scale Shape Discrimination), was developed in this study. Compared to the traditional PSD (Pulse Shape Discrimination) method, SSD has the advantage of transforming one-dimensional pulses in the time-domain into two-dimensional time-frequency spectra, providing the more useful features for pulse discrimination. The performances of the Compton suppression and Full-energy peak loss using PSD and SSD methods was studied. The results show that the Compton suppression factor IPSD = 5.12 and ISSD = 5.32, and FEP loss factor PLPSD = 0.0554 and PLSSD = 0.0587. Meanwhile, the influences of the cutoff values for pulse discrimination on the results of I and PL with different method were analyzed.

Purpose Charged particle cascade simulations, in conjunction with finite element thermal and mechanical calculations, are essential for addressing engineering challenges associated with the design of accelerator beam dumps. This study aims to investigate the integration of the FLUKA Monte Carlo program and the COMSOL finite element program as indispensable tools in the development of advanced models for spatial energy deposition distributions, temperature assessments, and stress analysis within the DALS beam dump. Methods The paper delves into aspects of model development, data transfer, and practical applications, focusing on the successful coupling of FLUKA Monte Carlo simulations with COMSOL finite element analyses. Tens of millions of elements were created and utilized to estimate spatial energy deposition distributions, assess temperatures, and analyze stresses within the critical absorber of the DALS beam dump. The study comprehensively analyzes the process from the impact of high-energy electron beam on the beam dump to the spatial distribution of energy deposition, providing input for subsequent thermal and structural analyses. Results The successful coupling of FLUKA and COMSOL enabled the calculation of spatial temperature distributions and structural analyses of the absorber within the DALS beam dump. The utilization of tens of millions of defined bins ensured seamless data transfer from the particle cascade simulation to finite element analysis, guaranteeing high resolution and accuracy in the calculations. The results provide valuable insights into the thermal and mechanical behavior of the beam dump absorber, a critical safety component in accelerator systems. Conclusions The study demonstrates that the integration of FLUKA Monte Carlo simulations with COMSOL finite element analyses is a dependable and efficient tool for addressing real-world engineering challenges, particularly those related to the design of beam dumps in accelerator systems with charged particle beams. The advanced analytical approach provides crucial information for the optimal design and safety assessment of accelerator components.

The fission model, G4ParaFissionModel, was enhanced in this study, mainly focusing on refining the energy dependence of the peak-to-valley ratio in the mass distribution and the energy dependence of the average total kinetic energy (TKE). The enhanced model was employed to investigate the characteristics of fission products from 235U(n, f) reaction. The calculated results, including fission yield, TKE distribution, prompt fission neutron and gamma spectra, were compared with both evaluated and experimental data. The comparison shows that these physical observables related nuclear data, which are of importance for developments of the nuclear power and physics, can be reasonably well reproduced.

In this study, the response of a Twin Frisch-grid ionization chamber (TFGIC) to fission fragments (FFs) was investigated using finite element and Monte Carlo methods. The entire process of the fission experiments, including FFs generation, gas ionization, electron drift and collection, and induced charge signal were well reproduced. Through data analysis, pulse height spectra from the anode and grid were transformed into energy and emission-angle information for the FFs. By means of double energy method, the pre-neutron emission fission fragment mass and total kinetic energy (TKE) can be finally determined. Experimental and calculated data of the mass and TKE distribution are shown in good agreement.

Abstract In this study, the grid inefficiency $$\sigma $$ σ for a mesh-type Frisch-grid ionization chamber (FGIC) was investigated using the finite element method and Monte Carlo method. A grid inefficiency $$\sigma $$ σ evaluation model was developed, which can determine the relationship between the physical parameters of the detector and the grid inefficiency with reasonable accuracy. An artificial neural network (ANN) was applied in the investigation of the grid inefficiency factor $$\sigma $$ σ . The trained ANN was able to describe and predict the grid inefficiency factor $$\sigma $$ σ with different physical parameters for the mesh-type FGIC. Thus, it can serve as a reference for the development of mesh-type FGICs and correct grid inefficiency $$\sigma $$ σ measurements.

The electron beam dump for Dalian Advanced Light Source (DALS) is designed to absorb 15 kW of electron beam power at beam energy up to 120 MeV. The DALS accelerator produces an electron beam with very small beam size of up to 100 μA average current. The resulting beam power, up to 15 kW at 120 MeV, and the very high beam power density, pose challenging problems for beam dump design. High power dump with water cooled has been developed for DALS. In the dump, most of the beam power is finally absorbed in water and taken out from the dump. The core of the high power electron beam dump is designed to be constructed from an aluminum alloy using a cylindrical geometry with fins arranged around to promote the heat transfer. The cooling water is forced by a cooling pump, to cool the core of the dump through the cooling channels. The beam is stopped in the dump involving a high production of neutron and gamma radiation and activation of its surface. A shield has been designed to attenuate both the radiation produced during accelerator operation and the residual radiation. Design details for the dump, including radiation shielding calculations, thermal analysis are presented.