On the drive of modes by ICRF accelerated ions in a tokamak
Energetic ions have the potential to drive instabilities with toroidal mode number $n_{\phi} = 0$ in tokamak fusion plasmas. A necessary condition is that their distribution function is either anisotropic or exhibits a region of phase space with a positive slope in the energy direction (so-called ‘b...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | Nuclear Fusion |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1741-4326/adf79e |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849239315778895872 |
|---|---|
| author | L.-G. Eriksson F. Porcelli |
| author_facet | L.-G. Eriksson F. Porcelli |
| author_sort | L.-G. Eriksson |
| collection | DOAJ |
| description | Energetic ions have the potential to drive instabilities with toroidal mode number $n_{\phi} = 0$ in tokamak fusion plasmas. A necessary condition is that their distribution function is either anisotropic or exhibits a region of phase space with a positive slope in the energy direction (so-called ‘bump-on-tail’ distribution). Here an exploration of both possibilities is presented for Ion Cyclotron Range of Frequency (ICRF) accelerated energetic ions. It is found that ion cyclotron resonance layers placed on the high-field side of the magnetic axis provide the most conducive conditions for the drive of vertical $n_{\phi} = 0$ modes. We also discuss to what extent sawtooth redistribution of the ICRF accelerated ions can transiently lead to distribution functions that are locally inverted in the energy direction. However, the latter effect appears to be less efficient in driving $n_{\phi} = 0$ vertical modes than velocity space anisotropy for high-field-side resonances. |
| format | Article |
| id | doaj-art-965b7042a1fe45f19f75e9bc5b3a0163 |
| institution | Kabale University |
| issn | 0029-5515 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Nuclear Fusion |
| spelling | doaj-art-965b7042a1fe45f19f75e9bc5b3a01632025-08-20T04:01:02ZengIOP PublishingNuclear Fusion0029-55152025-01-0165909200510.1088/1741-4326/adf79eOn the drive of modes by ICRF accelerated ions in a tokamakL.-G. Eriksson0https://orcid.org/0009-0004-1375-9929F. Porcelli1https://orcid.org/0000-0002-3625-6417Department of Space, Earth and Environment, Chalmers University of Technology , Gothenburg SE-412 96, SwedenDepartment of Applied Science and Technology, Polytechnic University of Turin , Torino 10129, ItalyEnergetic ions have the potential to drive instabilities with toroidal mode number $n_{\phi} = 0$ in tokamak fusion plasmas. A necessary condition is that their distribution function is either anisotropic or exhibits a region of phase space with a positive slope in the energy direction (so-called ‘bump-on-tail’ distribution). Here an exploration of both possibilities is presented for Ion Cyclotron Range of Frequency (ICRF) accelerated energetic ions. It is found that ion cyclotron resonance layers placed on the high-field side of the magnetic axis provide the most conducive conditions for the drive of vertical $n_{\phi} = 0$ modes. We also discuss to what extent sawtooth redistribution of the ICRF accelerated ions can transiently lead to distribution functions that are locally inverted in the energy direction. However, the latter effect appears to be less efficient in driving $n_{\phi} = 0$ vertical modes than velocity space anisotropy for high-field-side resonances.https://doi.org/10.1088/1741-4326/adf79etokamakaxisymmetric modesion cyclotron resonance frequency accelerated ions |
| spellingShingle | L.-G. Eriksson F. Porcelli On the drive of modes by ICRF accelerated ions in a tokamak Nuclear Fusion tokamak axisymmetric modes ion cyclotron resonance frequency accelerated ions |
| title | On the drive of modes by ICRF accelerated ions in a tokamak |
| title_full | On the drive of modes by ICRF accelerated ions in a tokamak |
| title_fullStr | On the drive of modes by ICRF accelerated ions in a tokamak |
| title_full_unstemmed | On the drive of modes by ICRF accelerated ions in a tokamak |
| title_short | On the drive of modes by ICRF accelerated ions in a tokamak |
| title_sort | on the drive of modes by icrf accelerated ions in a tokamak |
| topic | tokamak axisymmetric modes ion cyclotron resonance frequency accelerated ions |
| url | https://doi.org/10.1088/1741-4326/adf79e |
| work_keys_str_mv | AT lgeriksson onthedriveofmodesbyicrfacceleratedionsinatokamak AT fporcelli onthedriveofmodesbyicrfacceleratedionsinatokamak |