Geant4-TRIM interface for damage calculations in interactions between neutrons and matter

• Grant number: 22/07328-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2022
• End date: August 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Sandro Guedes de Oliveira
• Grantee: Ivan Prearo
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The interaction between neutrons and matter is commonly studied for applications such as shielding or rare event experiments that take neutrons as a background signal. One of the most detailed calculation methods is the simulation of neutron irradiation in the studied materials, quantifying the number and energy of neutron-nucleus collisions. The Norgett-Robinson-Torrens (NRT) model is then used as an analytical method to quickly calculate the number of vacancies caused in each collision and therefore, in the material as a whole. Nonetheless, the NRT model lacks information about the spatial distribution of these defects, needing separate estimates for a more realistic image of the situation in case of non-punctual defects. A more detailed calculation can be obtained through Monte Carlo simulation, such as that implemented in the code Transport of Ions in Matter (TRIM). The disadvantages are the time necessary to complete the calculations and the lack of an interface between programs that calculate the neutron interactions and TRIM, which calculates the interactions from the secondary ions generated in these interactions. We shall use the tools made available by the Geant4 platform to develop a simulator for neutron incidence that automatically invokes TRIM that will perform the simulations of knocked atoms, calculating the resulting number of vacancies, instead of the NRT model. We will create a setting to be simulated that can be used to describe situations that do not depend strongly on the sample geometry, increasing the number of uses for this new program. Likewise, we shall also develop an R graphic interface for parameter input and summarization of the results. Our method validation will be the reproduction of irradiations from works in the literature in order to compare the defect density distributions obtained.(AU)