The wall conditioning experiment by Li–Si coating in the HL-1M tokamak

The mixture coating of lithium and silicon, which is called ‘Li–Si coating’ for short, is formed on the plasma facing wall of HL-1M by means of direct current glow discharge with the mixture of lithium vapor and monosilane and helium. In HL-1M after Li–Si coating, the most favorable vacuum condition is obtained and, the impurities and recycling are restrained forcefully in plasma discharges. By once Li–Si coating, about two hundred quality shots are performed in HL-1M. The experimental results show that the Li–Si coating is of advantages of Li coating and siliconization but weakens their defects.