Effects of stainless steel and tungsten on a hard X-ray diagnostics system in the Experimental Advanced Superconducting Tokamak (EAST)

Abstract

Attenuation coefficients of γ-rays in stainless steel, lead, and tungsten were calculated theoretically. According to the theoretical calculations, cylindrical lead shielding and a collimator were designed for a high-energy hard X-ray spectrum diagnostic system in the Experimental Advanced Superconducting Tokamak (EAST). The hard X-ray diagnostic system of EAST was introduced in detail, and the diagnostic system was tested through table experiments with radioactive 22Na sources. Attenuation coefficients of γ rays in stainless steel and tungsten were also obtained by fitting γ-ray radiation spectra. The effect of the stainless steel and tungsten materials on the X-ray and γ-ray diagnostic system was evaluated by γ-ray energy spectra. The attenuation coefficients obtained through the experiments were found to agree well with those calculated theoretically considering the error. The influence of stainless steel on low-energy X-ray or γ-ray diagnostics cannot be ignored, while its influence on high-energy X-ray or γ-ray diagnostics can be ignored. The influence of tungsten on X-ray or γ-ray diagnostics cannot be ignored. However, high Z materials such as tungsten and lead should be avoided in front of the collimation hole of the detector to reduce the influence on diagnostic data.

Keywords

• tokamak
• hard x-ray
• tungsten
• stainless steel
• attenuation coefficient