Measurement of Displacement Cross Section of Structural Materials Utilized in the Proton Accelerator Facilities with the Kinematic Energy above 400 MeV

Shin-Ichiro Meigo,Shoichi Hasegawa,Yosuke Iwamoto,Shunsuke Makimura,Tatsushi Nakamoto,Fujio Maekawa,Makoto Yoshida,Hiroki Matsuda,Hiroki Iwamoto,Taku Ishida

doi:10.7566/jpscp.28.061004

Abstract

For damage estimation of structural material in the accelerator facility, displacement per atom (DPA) is widely employed as an index of the damage calculated based on the displacement cross section obtained with the calculation model. Although the DPA is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. Among the calculation models, the difference exists about 8 times so that experimental data of the displacement cross section is crucial to validate the model. To obtain the displacement cross section, we conducted the experiment in J-PARC. As a preliminary result, the displacement cross section of copper was successfully obtained for 3-GeV proton. The present results showed that the widely utilized the Norgertt-Robinson-Torrens (NRT) model overestimates the cross section as suggested by the previous experiment for protons with lower energy.

Highlights

To decrease hazard of the radioactive waste produced in a nuclear reactor, Japan Atomic EnergyAgency (JAEA) proposes the Accelerator Driven System (ADS) with extremely high power accelerator such as 30 MW with proton kinetic energy of 1.5 GeV
Where φ(E) is average proton flux over the sample surface accumulated for irradiation time, ρFP is the resistivity change per Frenkel-pair density for a particular metal
The degradation compromises quench protection and increases magnetothermal instability, for the superconducting accelerator magnet utilized in the hadron collider such as High-Luminosity Large Hadron Collider (LHC) in CERN

Summary

Introduction

Agency (JAEA) proposes the Accelerator Driven System (ADS) with extremely high power accelerator such as 30 MW with proton kinetic energy of 1.5 GeV. In the design of the ADS, damage to the beam intercepting material is one of a critical issue. In other high-intensity accelerator facilities, beam intercepting material plays essential roles. Facility (MLF) [1, 2] in J-PARC [3], an aluminum alloy is utilized as beam window [4] separating between high vacuum area and target station. To operate high power accelerator with confidence, damage estimation of the target material is essential. For the quantitative specification of the damage to the target material, displacement per atom (DPA) is employed in general. The DPA is widely used for the estimation of damage nuclear reactor and fusion reactor as well

Methods

Discussion

Conclusion