Benign termination of runaway electron beams on ASDEX Upgrade and TCV

• DOI: 10.1088/1361-6587/ad1e31
• Publication Date: 2024-01-12T22:56:37Z
• Authors: U Sheikh; J Decker; M Hoppe; M Pedrini; B Sieglin; L Simons; J Cazabonne; J Caloud; J Cerovsky; S Coda; C Colandrea; A Dal Molin; B Duval; O Ficker; M Griener; G Papp; G Pautasso; C Paz-Soldan; C Reux; E Tomesova; T Wijkamp; the ASDEX Upgrade...
• Keywords: ASDEX Upgrade; Collisionality

Abstract This paper discusses the development of a benign termination scenario for runaway electron (RE) beams on ASDEX Upgrade and TCV. A systematic study revealed that low density ( n e ) companion plasma was required to achieve large MHD instability, which expelled confined REs over wetted area allowed conversion magnetic energy radiation. Control achieved via neutral pressure regulation agnostic material injection method. The recombination found be dependent impurity species, quantity RE current. On TCV, increased at pressures above 1 Pa, indicating higher collisionality between neutrals may lead an upper limit. radiated measured both machines decrease in efficiency observed high technique able prevent any significant increase maximum heat flux AUG from 200 600 kA current, highlighting ability this approach handle fully formed beams.