Thermal wall load control using fast gas puffing in the TPE-RX reversed-field pinch

In order to reduce the thermal wall load due to the phase- and wall-locked modes particularly in the high plasma current regime, neutral gas puffing experiments have been conducted in the TPE-RX reversed-field pinch. The temperature of the plasma-facing wall at the mode-locking position sometimes exceeds the melting temperature of stainless steel. It has been determined that the maximum temperature increment of the wall becomes almost half in the neon and deuterium gas puffing cases at a plasma current of 350 kA. This indicates that neutral gas puffing can reduce the severe thermal wall load. The radiative cooling around the peripheral region as a result of neon gas puffing and the decrease in the heat flux along local magnetic field lines as a result of deuterium gas puffing are possible reasons behind the decrease in the rate of energy flow to the wall.