Physics and Engineering Aspects of the ICRF Heating System on EAST

Full text: Experimental Advanced Superconducting Tokamak (EAST) has been built to perform advanced tokamak research in high performance regime and to explore methods for achieving a steady-state operation for a tokamak fusion reactor. Radio frequency (RF) power in the ion cyclotron range of frequencies (ICRF) will be one of the primary auxiliary heating techniques for EAST. The ICRF system provides 6 MW power in primary phase and will be capable of 10 MW later. Two 1.5 MW ICRH systems in the range of 25-70 MHz have been put into operation. ICRH system includes High-power and wide-frequency radio amplifier, the phase shifter system, the matching system and two antenna. The ICH launchers are designed to have two current straps and each strap is driven by an independent 1.5 MW RF power source. Maximum of the injected RF power reached to 800 kW using a single strap. Two ICRH systems are being employed for RF heating experiment on EAST. Heating scheme are analyzed by using a parallel version of TORIC, a finite Larmor radius ICRF code. Three physical scenarios are considered: (a) Fast Wave (FW) minority heating; (b) FW mode conversion electron heating; (c) FW Second harmonic heating. The available diagnostic capability allows comparing experiments with the simulations and investigating different heating scenarios to address several key ICRF physical issues, such as effect of electron and ion heating, flow driven, production of energetic particles, etc. This paper gives an overview of the main technical features of the EAST ICRH system and especially first primary results on the EAST tokamak during present campaign. (author)