The role of kinetic instabilities in formation of the runaway electron current after argon injection in DIII-D

Lvovskiy, A.; Paz-Soldan, C.; Eidietis, N. W.; Dal Molin, A.; Du, X. D.; Giacomelli, L.; Herfindal, J. L.; Hollmann, E. M.; Martinelli, L.; Moyer, R. A.; Nocente, M.; Rigamonti, D.; Shiraki, D.; Tardocchi, M.; Thome, K. E.

Angol nyelvű Tudományos Szakcikk (Folyóiratcikk)
Megjelent: PLASMA PHYSICS AND CONTROLLED FUSION 0741-3335 1361-6587 60 (12) Paper: 124003 , 10 p. 2018
  • SJR Scopus - Condensed Matter Physics: D1
Azonosítók
Szakterületek:
    Kinetic instabilities in the MHz range driven by runaway electrons (REs) have been observed for the first time during the current quench (CQ) in disruptions triggered by massive injection of argon in DIII-D. These instabilities are well-correlated with intermittent RE losses in the beginning of RE current formation. The runaway current phase is not observed when the power of instabilities exceeds a threshold. Novel measurements of the RE distribution function during the CQ indicate that the instabilities appear when RE energy (E-RE ) exceeds 2.5-3 MeV, the number of modes grows linearly with E-RE , and their frequencies lie in the range 0.1-3 MHz, below the ion cyclotron frequency. Possible plasma waves exciting by REs in this region are proposed. Increase of the amount of injected argon decreases the E-RE and increases the success rate of the runaway current formation, while increase of the pre-disruption plasma current acts in the opposite direction. No dependence on the pre-disruption core electron temperature is found.
    Hivatkozás stílusok: IEEEACMAPAChicagoHarvardCSLMásolásNyomtatás
    2020-08-10 21:05