Session: 02-10: Physics and Transport Theory - II

Paper Number: 135163

135163 - Improved Athermal Recombination Corrected Dpa Model for Displacement Damage Cross-Section Calculation 

Abstract: 

Accurate evaluation of material irradiation damage is the basis for safe and economical operation of nuclear facilities, such as nuclear reactors. Displacement damage is an important component of material irradiation damage, and the level of displacement damage in materials is usually described by the displacement damage rate. The estimation of displacement damage rate requires the prior knowledge of displacement damage cross section and displacement function model is the key to the displacement damage cross section calculation. Since the 1970s, the Norgett−Robinson−Torrens displacements per atom (NRT-DPA) model has become the “standard” displacement damage function model for displacement damage cross section calculations. The NRT-DPA model overestimates the number of displaced atoms produced by primary knock-on atom (PKA) because it cannot consider the in-cascade recombination effects on defect production. To consider the in-cascade recombination effects, the athermal recombination corrected displacements per atom (ARC-DPA) model is proposed. However, both the NRT-DPA model and ARC-DPA model have significant errors in the calculation of the displacement damage function near the average atomic displacement threshold energy because they use the step function approximately for the calculation of the number of displaced atoms. In order to improve the accuracy of displacement damage cross section calculation, an improved ARC-DPA (iARC-DPA) model is proposed, which uses the power function model near the average atomic displacement threshold energy and original ARC-DPA model in the other energy part. And the beginning energy where the displaced atoms are produced is changed from the average atomic displacement threshold energy in NRT-DPA model or ARC-DPA model to the minimum atomic displacement threshold energy in the iARC-DPA model. The iARC-DPA model has been used in the calculation of displacement damage cross sections for different particles, including neutron, electron, photon and charged particles. In order to validate the improvement of the iARC-DPA model for the calculation of displacement damage cross section, some experimental data are obtained based on damage rate which are got by experiments. The displacement damage cross sections of different particles are calculated and compared with the experimental data. Numerical results show that the iARC-DPA model largely improves the accuracy of displacement damage cross section calculation. For electrons and neutrons, the deviations of C/E values (ratio of calculated to experimental values) can be reduced from about 50% to about 10%. In order to illustrate the influence of displacement damage cross section on displacement damage rate, displacement per atom (DPA) is calculated for some typical materials in different reactors and other nuclear facilities. Numerical results show that the iARC-DPA model reduces the DPA value obviously.

Presenting Author: Wen Yin Harbin Engineering University

Presenting Author Biography: Wen Yin, Ph.D. in Engineering, Associate Professor, received the B.S. degree in Nuclear Engineering and Technology from South China University of Technology in 2017, the Ph.D. degree in Nuclear Science and Technology from Xi'an Jiaotong University in 2023, and a one-year study visit to Karlsruhe Institute of Technology during the Ph.D. period. My main research interests include the study of displacement damage cross-section calculation methods, resonance calculation methods, nuclear data processing methods, nuclear data library production methods for reactors, and the development and application of nuclear data related codes. I have published more than 20 papers.

Authors:

Wen Yin Harbin Engineering University
Tiejun Zu Xi’an Jiaotong University
Liangzhi Cao Xi’an Jiaotong University