Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source. (15th February 2018)

• Record Type: Journal Article
• Authors: Jain, P; Recchia, M; Cavenago, M; Fantz, U; Gaio, E; Kraus, W; Maistrello, A; Veltri, P
• Is Part Of: Plasma physics and controlled fusion. Volume 60:Number 4(2018:Apr.)
• Publication Date: 2018-02-15
• Subjects: power transfer -- frequency variation -- inductively coupled -- stochastic heating -- transformer model -- ion sources -- efficiency; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/aaab19
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (∼9.4 W cm −3 ) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).