TY  - JOUR
AU  - Abdullaev, S. S.
AU  - Finken, K. H.
AU  - Wongrach, K.
AU  - Tokar, M.
AU  - Koslowski, H. R.
AU  - Willi, O.
AU  - Zeng, L.
TI  - Mechanism of runaway electron beam formation during plasma disruptions in tokamaks
JO  - Physics of plasmas
VL  - 22
IS  - 4
SN  - 1089-7674
CY  - [S.l.]
PB  - American Institute of Physics
M1  - FZJ-2015-03026
SP  - 040704 
PY  - 2015
AB  - A new physical mechanism of formation of runaway electron beams during plasma disruptions in tokamaks is proposed. The plasma disruption is caused by a strong stochastic magnetic field formed due to nonlinearly excited low-mode number magnetohydrodynamic (MHD) modes. It is conjectured that the runaway electron beam is formed in the central plasma region confined inside the intact magnetic surface located between q = 1 and the closest low–order rational magnetic surfaces [q = 5/4 or q = 4/3,…]. It results in that runaway electron beam current has a helical nature with a predominant m/n = 1/1 component. The thermal quench and current quench times are estimated using the collisional models for electron diffusion and ambipolar particle transport in a stochastic magnetic field, respectively. Possible mechanisms for the decay of the runaway electron current owing to an outward drift electron orbits and resonance interaction of high–energy electrons with the m/n = 1/1 MHD mode are discussed.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000353837200005
DO  - DOI:10.1063/1.4919253
UR  - https://juser.fz-juelich.de/record/190067
ER  -