Experimental and numerical evaluation of the neutral beam deposition profile in KSTAR

Abstract

In this article the neutral beam deposition profile of each neutral beam source in KSTAR is reported. Since the neutral beam system of KSTAR is the main heating and current drive source, it is crucial to estimate and reconstruct the neutral beam deposition profile with high accuracy. A fully non-inductive discharge experiment is conducted to minimize Ohmic current effect on the interpretation. An each beam source is switched off one by one longer than the current diffusion time scale. Reconstructed beam driven current is derived by extracting the total current profile from non-beam driven current components such as bootstrap, electron cyclotron, and Ohmic. By comparing numerical beam modeling, beam driven deposition profile per each beam source is quantitatively interpreted. © 2022 The Author(s)