Quantitative estimation of tritium amount in surface layer and bulk of tungsten sample using BIXS

Abstract

Estimation of both the surface tritium and tritium in bulk in key materials of fusion reactors is of great importance for tritium safety and the management of tritium-contaminated material. For the further quantitative analysis of tritium in solids, the elaborate BIXS spectra were calculated based on Monte Carlo simulation. Four types of tritium depth profile were considered to evaluate the quantitative estimation method. It is found that the attenuation of X-rays in tungsten depends on both the energy of X-rays and the depth of X-rays. The evaluation of tritium amount in surface layer indicated that the intensity of Ar(Kα) peak could be used to evaluate the surface tritium within 400 nm from the surface in most cases and the deviations were less than 9% in the calculation. The intensity of both W(Lα) X-rays and the high energy X-rays can be employed to roughly estimate the total tritium amount. For linearly decreasing and exponentially decreasing distribution, the maximum calculation deviations were 24.9% and 28.8%, respectively. While for Gaussian distribution, the maximum deviations were 146% and 53%, respectively. And it can also be used for tritium estimation in other materials.