TY - JOUR
T1 - Interpretation of ion cyclotron emission from sub-Alfvénic beam-injected ions heated plasmas soon after L-H mode transition in EAST
AU - Liu, Lunan
AU - Zhang, Xinjun
AU - Ochoukov, R.
AU - Zhang, Wei
AU - McClements, K.G.
AU - Dendy, R.O.
AU - Salewski, M.
AU - Zhu, Yubao
AU - Qin, Chengming
AU - Moseev, D.
AU - Bobkov, V.
AU - Chapman-Oplopoiou, B.
AU - Zalzali, A.
PY - 2024
Y1 - 2024
N2 - Ion cyclotron emission (ICE) at deuterium ion cyclotron harmonics, driven by sub-Alfvénic beam-injected deuterium ions, has been observed by the high-frequency B-dot probe in the EAST tokamak. The origin of ICE shifts from the plasma core to the plasma edge soon after an L-H mode transition, where the beam-injected deuterium ions have a relatively peak bump-on tail structure in the energy direction and a very intense pitch angle anisotropy. Based on the fast ion distribution function obtained from the TRANSP/NUBEAM code, together with a linear analysis theory of magnetoacoustic cyclotron instability (MCI), the growth rates of MCI could be calculated. It is shown that MCI, resulting in the generation of obliquely propagating fast Alfvén waves at deuterium ion cyclotron harmonics, can occur under such conditions. And the temporal evolution of the MCI growth rate closely follows that of the observed ICE amplitude in the EAST.
AB - Ion cyclotron emission (ICE) at deuterium ion cyclotron harmonics, driven by sub-Alfvénic beam-injected deuterium ions, has been observed by the high-frequency B-dot probe in the EAST tokamak. The origin of ICE shifts from the plasma core to the plasma edge soon after an L-H mode transition, where the beam-injected deuterium ions have a relatively peak bump-on tail structure in the energy direction and a very intense pitch angle anisotropy. Based on the fast ion distribution function obtained from the TRANSP/NUBEAM code, together with a linear analysis theory of magnetoacoustic cyclotron instability (MCI), the growth rates of MCI could be calculated. It is shown that MCI, resulting in the generation of obliquely propagating fast Alfvén waves at deuterium ion cyclotron harmonics, can occur under such conditions. And the temporal evolution of the MCI growth rate closely follows that of the observed ICE amplitude in the EAST.
KW - Ion cyclotron emission
KW - Magnetoacoustics cyclotron instability
KW - Beam-injected fast ions
KW - Tokamak
U2 - 10.1088/1361-6587/ad0fa6
DO - 10.1088/1361-6587/ad0fa6
M3 - Journal article
SN - 0741-3335
VL - 66
JO - Plasma Physics and Controlled Fusion
JF - Plasma Physics and Controlled Fusion
IS - 1
M1 - 015007
ER -