STUDY OF HELIUM TRANSPORT IN HL-1M EDGE PLASMA REGION

Radial profiles of the emission intensity for H-alpha and neutral heli um line (lambda = 5875.7 Angstrom) are measured to study helium transp ort and recycling in the HL-1M edge region in the vicinity of the polo idal graphite limiter (at r = 26 cm) after previous helium glow discha rge cleaning and boronization under different LHCD and ECH conditions. A one-dimensional Monte Carlo neutral helium transport code, 1DHET, i s utilized to calculate neutral helium density profile in the same reg ion. The comparisons show that the freshly boronized wall with helium glow discharge cleaning exhibits somewhat selective recycling characte ristics between the helium and hydrogen atoms, if ECH power is not app lied.