ICRF wall conditioning and plasma performance on EAST

ICRF (ion cyclotron resonance frequency) wall conditioning was performed on EAST superconducting tokamak. It included ICRF cleaning in-between shots, boronization associated with ICRF plasmas, and ICRF oxidation with an ITER-relevant full metallic wall material. A dedicated ICRF antenna was developed for wall conditioning on EAST. The RF frequency is 30 MHz, and maximum output power of RF system is 300 kW. The duty time of pulsed ICRF wave was set at 0.3 s on and 1.2 s off in presence of the toroidal magnetic field of 1-2 T. Optimization of start-up, ramp-up and plasma shaping for single and double-null configurations were obtained following the ICRF wall conditioning. High density, high plasma current and long pulse discharges were achieved on EAST. (C) 2009 Elsevier B.V. All rights reserved.