An upper pressure limit for low-Z benign termination of runaway electron beams in TCV

• DOI: 10.1088/1361-6587/adbcd5
• Publication Date: 2025-03-05T22:51:57Z
• Authors: M Hoppe; J Decker; U Sheikh; S Coda; C Colandrea; B Duval; O Ficker; P Halldestam; S Jachmich; M Lehnen; H Reimerdes; C Paz-Soldan; M Pedrini; C Reux; L Simons; B Vincent; T Wijkamp; M Zurita

Abstract We present a model for the particle balance in post-disruption runaway electron plateau phase of tokamak discharge. The is constructed with help of, and applied to, experimental data from TCV discharges investigating so-called ‘low- Z benign termination’ mitigation scheme. In termination scheme, free density first reduced order subsequently induced MHD instability to grow rapidly spread electrons widely across wall. show that observed non-monotonic dependence measured neutral pressure due plasma re-ionization by impact ionization. At higher pressures, more target particles are collide ionize. Parameter scans conducted clarify role energy on density, it found only has noticeable impact. While shown be related heat fluxes at termination, exact cause upper limit remains undetermined an object further study.