Simulation of neutron transmission performance of metallic spherical shell under temperature dependent neutron cross section

Yinghong Zuo,Jinhui Zhu,Honggang Xie,Z Ge,H Zhang,N Shu,W Wang,Y Chen

doi:10.1051/epjconf/202023903017

Yinghong Zuo, Jinhui Zhu + Show 6 more

Open Access

https://doi.org/10.1051/epjconf/202023903017

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Abstract

To study the effect of temperature dependent neutron cross section on the neutron transmission performance of typical metallic spherical shells, this paper generated the temperature dependent neutron cross section data by using NJOY program, and established the computational model of interaction of neutron with iron and aluminium spherical shell. The temperature evolution of energy spectrum of transmitted neutron and secondary gamma ray, and the number ratio of transmitted neutrons to secondary gamma rays has been studied at various neutron energies. The results show that only when the energies of the incident neutron are in a certain range, the temperature dependent cross sections can have a significant effect on the energy spectrum of the rays penetrating the spherical shell. For different metal materials, the transmitted neutron spectrum and the secondary gamma ray spectrum will be significantly affected when the temperature increases to different high value. Generally, the transmitted neutron number decreases with the increase of temperature, and the number ratio of transmitted neutron to secondary gamma ray also decreases with the increase of temperature, while the changing trend of number of secondary gamma ray with temperature is related to the type of shell material.

Highlights

The energy-related nuclear cross-section data is indispensable when the Monte Carlo program MCNP is used to do a simulation of particle transport [1]
For MCNP program, the neutron cross section data in A Compact ENDF format can be produced by using NJOY program
For the spherical shell model shown in figure 1, the MCNP4C program and the F1 tally card are used to calculate the spectrum of the secondary gamma-ray and the number ratio of the transmitted neutron to the secondary gamma ray of the isotropic neutron source interacting with iron or aluminum spherical shells with different thicknesses

Summary

Introduction

The energy-related nuclear cross-section data is indispensable when the Monte Carlo program MCNP is used to do a simulation of particle transport [1]. In temperaturedependent particle transport simulation, for most nuclides without thermal cross section, MCNP program only modifies the elastic scattering cross section of the thermal part by Maxwell temperature [3,4]. To obtain more accurate simulation results of temperature-dependent particle transport using MCNP program, it is necessary to develop a temperature-dependent neutron cross section database. NJOY [5], which is widely used in the world, can process the original ENDF [6,7] format evaluation database into nuclear cross section data for different simulation programs such as MCNP, ANISN and WIMS. For MCNP program, the neutron cross section data in A Compact ENDF format can be produced by using NJOY program. In order to study the rules of interaction between radiation and matters at higher temperatures, i.e. when nuclear materials are in plasma state, the temperature-dependent neutron cross section data is

Physical model and method

Interaction between monoenergy neutron and Fe spherical shell

Interaction between monoenergy neutron and aluminum spherical shell

Interaction between fission neutron source and metallic spherical shell

Conclusions