Advanced β-ray-induced X-ray spectrometry for non-destructive measurement of tritium retained in fusion related materials

A new β-ray-induced X-ray measurement system equipped with a silicon drift detector, which was named “Advanced-BIXS”, was constructed to study in detail retention behavior of surface tritium by measurements of low energy X-rays below 1 keV such as C(Kα) and O(Kα) as well as high energy X-rays induced by β-rays from tritium. In this study, basic performance of the present system has been examined using various tritium-containing samples. It was seen that energy linearity, energy resolution and sensitivity were quite enough for measurements of low energy X-rays induced by β-rays. Intensity of characteristic X-rays emitted from the surface and/or bulk of a tritium-containing sample was lowered by argon used as a working gas of the Advanced-BIXS. Pressure dependence of transmittance of C(Kα) and Fe(Kα) was examined as examples of low and high energy X-rays, and it was able to represent by using the mass absorption coefficient in argon. It was concluded, therefore, that the present system has high potentiality for nondestructive measurements of tritium retained in surface layers and/or bulk of fusion related materials.