Hot spots and bright patterns on plasma-facing components (PFC) in visible light are observed in electron cyclotron resonance heated (ECRH) plasmas at low densities in the stellarator Wendelstein 7-X. The events are often located far outside of any convective plasma loads and led in some cases to damages of diagnostic components, where the interaction zones qualitatively agree with fast particle loss simulations. Reciprocating electric probes indicate that this phenomenon is related to a non-thermal electron population that can have a beam like character, being directed in one parallel direction. Further, the electrons can be trapped on rational flux surfaces and be used to map magnetic islands.
Observation of non-thermal electrons outside the SOL in the Wendelstein 7-X stellarator
Spolaore M;
2022
Abstract
Hot spots and bright patterns on plasma-facing components (PFC) in visible light are observed in electron cyclotron resonance heated (ECRH) plasmas at low densities in the stellarator Wendelstein 7-X. The events are often located far outside of any convective plasma loads and led in some cases to damages of diagnostic components, where the interaction zones qualitatively agree with fast particle loss simulations. Reciprocating electric probes indicate that this phenomenon is related to a non-thermal electron population that can have a beam like character, being directed in one parallel direction. Further, the electrons can be trapped on rational flux surfaces and be used to map magnetic islands.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
