Radiation distribution for shattered pellet injection experiment with AXUV array diagnostics in KSTAR

• Published in: Fusion engineering and design Vol. 180; p. 113172
• Main Authors: Jang, Juhyeok, Kim, Jayhyun, Kim, Jaewook, Yoo, Jeongwon, Lehnen, M., Baylor, L.R., Eidietis, N.W., Shiraki, D., Park, Soohwan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-07-2022; Elsevier Science Ltd
• Subjects: Arrays; Diagnostic systems; Disruption; Medical imaging; Neon; Nuclear power plants; Pellets; Photodiodes; Plasma diagnostics; Radiation distribution; Radiation measurement; Shattered pellet injection; Tokamak; Tomography; Tokamak; Tomography; Shattered pellet injection; Plasma diagnostics; Disruption
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2022.113172

•The AXUV array diagnostics for shattered pellet injection experiments in KSTAR.•The poloidal AXUV arrays (PAAs) for poloidal cross-sectional radiation images.•The toroidal AXUV arrays (TAAs) for toroidal radiation distribution.•Strong radiation asymmetry for single SPI shots in KSTAR.•Radiated energy and CQ duration with various neon quantities in single SPI.
Shattered pellet injection (SPI) is the most promising technique for disruption mitigation in reactor-scale magnetic fusion devices such as ITER. For SPI experiments in KSTAR, an AXUV array diagnostic system has been developed to obtain the radiation distribution on the poloidal plane and in the toroidal direction during disruption. AXUV photodiodes enable faster radiation measurement than the sub-millisecond scale. A tomographic reconstruction code for poloidal AXUV arrays has been also developed and tested by synthetic images. For single SPI experiments in 2020, AXUV measurement with a tomography technique visualizes radiation images on the poloidal plane during disruptions. For single SPI, the radiation is highly peaked at the SPI position. A neon (Ne) concentration scan for single SPI shots shows that the radiation energy and current quench duration change significantly with the Ne quantity and saturate at high Ne concentration.