Benign termination of runaway electron beams on ASDEX Upgrade and TCVMax Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching, Germany.
Swiss Plasma Center (SPC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Swiss Plasma Center (SPC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Institute of Plasma Physics of the CAS, Za Slovankou 3, 182 00 Prague 8, Czech Republic.
Institute of Plasma Physics of the CAS, Za Slovankou 3, 182 00 Prague 8, Czech Republic.
Swiss Plasma Center (SPC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Swiss Plasma Center (SPC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Istituto per la Scienza e Tecnologia dei Plasmi, Consiglio Nazionale delle Ricerche, 20125 Milan, Italy.
Swiss Plasma Center (SPC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Institute of Plasma Physics of the CAS, Za Slovankou 3, 182 00 Prague 8, Czech Republic.
Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching, Germany.
Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching, Germany.
Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching, Germany.
Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, United States of America.
CEA-IRFM, F-13108 Saint-Paul-les-Durance, France.
Institute of Plasma Physics of the CAS, Za Slovankou 3, 182 00 Prague 8, Czech Republic.
FOM Institute DIFFER ‘Dutch Institute for Fundamental Energy Research’, 5600 HH Eindhoven, Netherlands.
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2024 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 66, no 3, article id 035003Article in journal (Refereed) Published
Abstract [en]
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 a low electron density (n e) companion plasma was required to achieve a large MHD instability, which expelled the confined REs over a large wetted area and allowed for the conversion of magnetic energy to radiation. Control of the companion plasma ne was achieved via neutral pressure regulation and was agnostic to material injection method. The neutral pressure required for recombination was found to be dependent on impurity species, quantity and RE current. On TCV, n e increased at neutral pressures above 1 Pa, indicating that higher collisionality between the REs and neutrals may lead to an upper pressure limit. The conversion of magnetic energy to radiated energy was measured on both machines and a decrease in efficiency was observed at high neutral pressure on TCV. The benign termination technique was able to prevent any significant increase in maximum heat flux on AUG from 200 to 600 kA of RE current, highlighting the ability of this approach to handle fully formed RE beams.
Place, publisher, year, edition, pages
IOP Publishing , 2024. Vol. 66, no 3, article id 035003
Keywords [en]
benign termination, disruptions, runaways
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:kth:diva-342822DOI: 10.1088/1361-6587/ad1e31ISI: 001146996500001Scopus ID: 2-s2.0-85183076248OAI: oai:DiVA.org:kth-342822DiVA, id: diva2:1833345
Note
QC 20240201
2024-01-312024-01-312024-02-06Bibliographically approved