Recycling and wall pumping in long duration discharges on TRIAM-1M

摘要

Recycling and wall pumping have been studied comparing low (≈10~18 m~-3) and high (≈10~19 m~3) density long duration plasmas in TRIAM-1M. the recycling coefficient of each plasma increases with time. There exist two time constants in the temporal evolution of the recycling coefficient. One is a few seconds and the other is bout 30 s. The wall pumping rates of low and high density plasmas are evaluated to be ≈1.5x10~16 atoms m~-2 s~-1 and ≈4 x 10~17 atoms m~-2 s~-1, respectively. The difference may be caused by the total number of diffused ions and the charge exchange neutral flux with an energy of less than 0.7 keV.