The Study Of Reduced Activation Ferritic/martensitic Steels And Tungsten Irradiated By Plasma In HT-7 Tokamak

For the fusion tokamak, the abilities of first wall material to resist fusion plasma irradiation are very important, this subject have been studied for many years in the world. In this dissertation, we mainly study the interaction of tokamak boundary plasma with two kinds of reduced activation ferritic/martensitic steels i.e. CLAM steel and EUROFER97 steel, and tungsten. Through inserting the samples to the scrape-off layer of HT-7 tokamak with a vacuum-tight transporter system, all samples were irradiated by 802 plasma discharges for 1200 seconds and then were analysed. We don't find radioactive isotope in all samples by Y -ray detector. Surface morphology observation with Scanning Electron Microscope(SEM) show some changes after plasma irradiation. It is easy to observe the dense small blisters on surfaces of CLAM steel, EUROFER97 steel and sparse big blisters on surface of tungsten. Plasma dust and trace irradiated by plasma are observed on some sample surfaces. X-ray photoelectron spectroscopy(XPS) shows that chemical compositions of the sample surfaces are changed, and the composition of silicon on sample surfaces varies with samples' distance from plasma duo to siliconization.