Speaker
Sung-Ryul Huh
(Nuclear Fusion Engineering Development Division)
Description
Within the framework for development of the radio frequency (RF) driven positive ion source as an alternative to the conventional filament arc driven ion source for fusion applications, KAERI is currently constructing a new high power (50 kW at a frequency of 2 MHz) large area RF ion source. The ion source was designed to have a rounded rectangular geometry for covering rectangular ion extraction area of 17 cm in width and 35 cm in length. An impedance matching circuit maximizing the power transfer to the plasma load in this RF ion source, while taking account of technical feasibility, has been designed. For the impedance matcher design, estimation of plasma load impedances depending on operating conditions is of paramount importance because it determines the required impedance tuning range, voltage withstand capability, and cooling power. The electromagnetic model and hydrogen plasma global model were employed to predict the RF power absorbed by the plasma and plasma parameters (i.e., electron density and electron temperature) versus RF input power, respectively. Especially, in the case of rounded rectangular geometry compared to the circular cross section, the electromagnetic model demands for a numerical approach due to more complicated boundary condition. These models enable one to obtain the expected plasma impedances dependent on RF input power up to 50 kW, leading to the calculation of designed values about tuning capacitances of vacuum variable capacitors in the impedance matching circuit, voltages and currents of the antenna and capacitors at matching conditions. In this work, the analyses for the impedance matching circuit design and designed values as their results are presented and discussed in detail.
Co-authors
Bong-Ki Jung
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
Doo-Hee Chang
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
Min Park
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
Seung-Ho Jeong
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
Sun-Ho Kim
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
Sung-Ryul Huh
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
Tae-Seong Kim
(Nuclear Fusion Engineering Development Division, Korea Atomic Energy Research Institute, Daejeon, South Korea)
