Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma

Vital to magnetized plasma performance, the acceleration of nonthermal electrons significantly influences the current drive of radio frequency (RF) waves in plasma. In Experimental Advanced Superconducting Tokamak (EAST), we observed nonthermal electrons initially <215 keV in energy, being locall...

Full description

Saved in:
Bibliographic Details
Main Authors: Chaowei Mai, Liqing Xu, Shiyao Lin, Liqun Hu, Yiping Chen, Tianfu Zhou, Xi Feng, Adi Liu, Zhengping Luo, Yan Chao, Haipeng Quan, Yubo Zhang
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
Series:Nuclear Fusion
Subjects:
Online Access:https://doi.org/10.1088/1741-4326/ad8bda
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850193785019957248
author Chaowei Mai
Liqing Xu
Shiyao Lin
Liqun Hu
Yiping Chen
Tianfu Zhou
Xi Feng
Adi Liu
Zhengping Luo
Yan Chao
Haipeng Quan
Yubo Zhang
author_facet Chaowei Mai
Liqing Xu
Shiyao Lin
Liqun Hu
Yiping Chen
Tianfu Zhou
Xi Feng
Adi Liu
Zhengping Luo
Yan Chao
Haipeng Quan
Yubo Zhang
author_sort Chaowei Mai
collection DOAJ
description Vital to magnetized plasma performance, the acceleration of nonthermal electrons significantly influences the current drive of radio frequency (RF) waves in plasma. In Experimental Advanced Superconducting Tokamak (EAST), we observed nonthermal electrons initially <215 keV in energy, being locally accelerated to 600 keV within 100 milliseconds, which corresponds to the total growth time of the magnetic island. Surprisingly, these fast electrons (FEs) lasted for 1.4 s, several times longer than the estimated relaxation time of 0.26 s, and exceeded 1/10 of the discharge length. Turbulence generation at island’s X point is attributed to the unexpected confinement and repopulation of FEs. This phenomenon may have positive implications for the steady-state long pulse H mode operation in EAST, especially regarding non-inductive current sustainment. For future RF electron heating-dominant devices, the mechanisms elucidated in this study have immediate implications for optimizing RF current drive efficiency.
format Article
id doaj-art-ba4ecf1db613423a9573b4bffd35fc4f
institution OA Journals
issn 0029-5515
language English
publishDate 2024-01-01
publisher IOP Publishing
record_format Article
series Nuclear Fusion
spelling doaj-art-ba4ecf1db613423a9573b4bffd35fc4f2025-08-20T02:14:10ZengIOP PublishingNuclear Fusion0029-55152024-01-0165101600110.1088/1741-4326/ad8bdaObservation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasmaChaowei Mai0https://orcid.org/0000-0001-9981-2620Liqing Xu1https://orcid.org/0000-0002-7388-6055Shiyao Lin2Liqun Hu3Yiping Chen4https://orcid.org/0000-0002-8045-6256Tianfu Zhou5Xi Feng6Adi Liu7https://orcid.org/0000-0002-3164-7320Zhengping Luo8Yan Chao9https://orcid.org/0000-0002-9957-2177Haipeng Quan10https://orcid.org/0009-0000-0420-034XYubo Zhang11Guangdong Ocean University , Zhanjiang 524088, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaUniversity of Science and Technology of China , Hefei 230026, People’s Republic of ChinaUniversity of Science and Technology of China , Hefei 230026, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of China; Anhui University of Science and Technology , Huainan 232001, People’s Republic of ChinaInstitute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei 230031, People’s Republic of China; University of Science and Technology of China , Hefei 230026, People’s Republic of ChinaVital to magnetized plasma performance, the acceleration of nonthermal electrons significantly influences the current drive of radio frequency (RF) waves in plasma. In Experimental Advanced Superconducting Tokamak (EAST), we observed nonthermal electrons initially <215 keV in energy, being locally accelerated to 600 keV within 100 milliseconds, which corresponds to the total growth time of the magnetic island. Surprisingly, these fast electrons (FEs) lasted for 1.4 s, several times longer than the estimated relaxation time of 0.26 s, and exceeded 1/10 of the discharge length. Turbulence generation at island’s X point is attributed to the unexpected confinement and repopulation of FEs. This phenomenon may have positive implications for the steady-state long pulse H mode operation in EAST, especially regarding non-inductive current sustainment. For future RF electron heating-dominant devices, the mechanisms elucidated in this study have immediate implications for optimizing RF current drive efficiency.https://doi.org/10.1088/1741-4326/ad8bdatokamakreconnectionaccelerationturbulence
spellingShingle Chaowei Mai
Liqing Xu
Shiyao Lin
Liqun Hu
Yiping Chen
Tianfu Zhou
Xi Feng
Adi Liu
Zhengping Luo
Yan Chao
Haipeng Quan
Yubo Zhang
Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
Nuclear Fusion
tokamak
reconnection
acceleration
turbulence
title Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
title_full Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
title_fullStr Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
title_full_unstemmed Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
title_short Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
title_sort observation of nonthermal electrons further acceleration and long lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
topic tokamak
reconnection
acceleration
turbulence
url https://doi.org/10.1088/1741-4326/ad8bda
work_keys_str_mv AT chaoweimai observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT liqingxu observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT shiyaolin observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT liqunhu observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT yipingchen observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT tianfuzhou observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT xifeng observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT adiliu observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT zhengpingluo observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT yanchao observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT haipengquan observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma
AT yubozhang observationofnonthermalelectronsfurtheraccelerationandlonglastingassociatedwithmagneticreconnectionandturbulenceburstingintokamakplasma