Development of Candidate Plasma Facing Materials for Steady State Operation of the HT-7U Superconducting Tokamak

A national project of the HT-7U superconducting tokamak is now under design and construction in ASIPP. Developing candidate materials for plasma facing components (PFC) of the HT-7U device is a crucial importance due to its operation circumstance under high heat flux and steady state. A series of doped CFC, multi-element doped graphite, thick SiC gradient coatings and tungsten coatings on carbon based materials (CBM) were developed by cooperation in China, evaluation experiments have been systematically performed in China and Japan by cooperation of Core University Program. The behavior of doped graphite and thick SiC gradient coatings on doped graphite under steady state and pulsed high heat flux, and HT-7 limiter plasma irradiation was investigated. Tungsten coating on CBM is now also under development being considered as one of the promising candidate plasma facing materials (PFM) for divertor plates of HT-7U device. The primary results about candidate PFM of HT-7U device are presented in this paper.