Role of Plasma Edge in the Direct Launch Ion Bernstein Wave Experiment in TFTR
Authors: M. Ono, C.E. Bush, R. Cesario, G.R. Hanson, J. Hosea, B. LeBlanc, R. Majeski, F. Paoletti, C.K. Phillips, J.H. Rogers, O. Sauter, G. Schilling, J.R. Wilson
Two types of direct IBW launching, EPW Þ IBW and CESICW Þ IBW are investigated using two numerical codes, Full Hot Plasma Ray-Tracing Code and SEMAL Full Wave Slab Code, for the TFTR direct launch IBW experimental parameters. The measured density profiles (by microwave reflectometry) in TFTR appear to be satisfactory for IBW launching while the observed stored energy rise compared to the expected value (ray tracing + TRANSP) indicates only up to 50% of launched power is reaching the plasma core. Possible causes of IBW inefficiency are also discussed.