Development of the ion cyclotron emission diagnostic on the HL-2A tokamak

Tong, R. H.; Fang, Kairui; Yu, Xiao; Liu, L.Z.; Shi, Z.B.; Yang, Z.C.; Zhong, W.L.; Zhou, Yan; Jiang, M.; Shi, P.W.; Wen, Jie; Deng, Wei; Xu, M.

doi:10.1088/1748-0221/17/01/c01063

Cited by 5 publications

(4 citation statements)

References 29 publications

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“…The ICE B-dot probes are mounted on the low field side (LFS) of the HL-2A NO port (at φ ≈ 45 • near NBI 1#), shown in figure 1(a) [70]. Three B-dot probes have been installed and the specific location is illustrated in figure 1(b).…”

Section: Methodsmentioning

confidence: 99%

Identification of core ion cyclotron instabilities on HL-2A tokamak

Liu,

Tong,

Zou

et al. 2023

Nucl. Fusion

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Instabilities in multiplies of ion cyclotron frequency range are identified and termed as core ion cyclotron emission (ICE) in recent HL-2A neutral beam injection (NBI) heated experiments. Characteristics of the core ICE are presented, including frequency dependence and harmonics features. The detected frequencies are found to agree well with the multiplies of the deuterium cyclotron frequency around the magnetic axis. Additionally, the core ICE exhibits a predominantly compressional property. Observations of distinct spectrum features and individual excitation of each harmonic have demonstrated that the core ICE harmonics are independent multiple modes. Notably, the variation of plasma current is a necessary condition for exciting the 4th harmonic ICE individually. The results suggest that the drive mechanism of core ICE varies between the different frequency ranges.

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Section: Methodsmentioning

confidence: 99%

Identification of core ion cyclotron instabilities on HL-2A tokamak

Liu,

Tong,

Zou

et al. 2023

Nucl. Fusion

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“…ICE was early observed from fusion-born ion populations in pure deuterium and DT plasmas in JET [1][2][3][4] and TFTR [5,6], and from neutral beam injected (NBI) ions in TFTR [7]. Since 2017, ICE has been detected and analysed from NBI and fusion-born ions in the KSTAR [8][9][10], DIII-D [11][12][13][14][15][16], ASDEX-Upgrade [17][18][19][20][21], NSTX-U [22,23], JT-60U [24][25][26], TUMAN-3M [27][28][29], EAST [30][31][32][33] and HL-2A [34,35] tokamaks, and the LHD heliotron-stellarator [36][37][38][39][40][41]. The magnetoacoustic cyclotron instability (MCI) has been identified as the excitation mechanism for ICE through analytical studies [6,7,42] and simulations [8-10, 12, 38, 39, 43-46].…”

Section: Introductionmentioning

confidence: 99%

Predicting ion cyclotron emission from neutral beam heated plasmas in Wendelstein7-X stellarator

Samant,

Dendy,

Chapman

et al. 2024

Nucl. Fusion

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Measurements of ion cyclotron emission (ICE) are planned for magnetically confined fusion (MCF) plasmas heated by neutral beam injection (NBI) in the Wendelstein 7-X stellarator (W-7X). Freshly injected NBI ions in the edge region, whose velocity-space distribution function approximates a delta-function, are potentially unstable against the magnetoacoustic cyclotron instability (MCI), which could drive a detectable ICE signal. Prediction of ICE from NBI protons in W-7X hydrogen plasmas is challenging, owing to the low ratio of the ions’ perpendicular velocity to the local Alfvén speed, v⊥(NBI)/vA ≃ 0.14. We address this from first principles, using the particle-in-cell (PIC) kinetic code EPOCH. This selfconsistently solves the Lorentz force equation and Maxwell’s equations for tens of millions of computational ions (both thermal majority and energetic NBI minority) and electrons, fully resolving gyromotion and hence capturing the cyclotron resonant phenomenology which gives rise to ICE. Our simulations predict an ICE signal which is predominantly electrostatic while incorporating a significant electromagnetic component. Its frequency power spectrum reflects novel MCI physics, reported here for the first time. The NBI ions relaxing under the MCI first drive broadband field energy at frequencies a little below the lower hybrid frequency ωLH, across the wavenumber range kωc/VA= 40 to 60, where ωc and VA denote ion cyclotron frequency and Alfvén velocity. Nonlinear coupling between these waves then excites spectrally structured ICE with narrow peaks, at much lower frequencies, typically the proton cyclotron frequency and its lower harmonics. The relative strength of these peaks depends on the specifics of the NBI ion velocity-space distribution and of the local plasma conditions, implying diagnostic potential for the predicted ICE signal from W7-X.

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“…In tokamak and stellarator, energetic particles often cause instability because of wave-particle resonances, which deteriorate confinement and result in fast-ion and electron loss that can damage the plasma-facing components [1]. The instability caused by energetic particles (ions and electrons) has been studied in numerous nuclear fusion devices, including ASDEX-U [2][3][4], DIII-D [5][6][7], KSTAR [8], JET [9,10], JT-60U [11], C-Mod [12], LHD [13,14], EAST [15,16], and HL-2A [17].…”

Section: Introductionmentioning

confidence: 99%

Radio-frequency measurements of energetic-electron-driven emissions using high-frequency magnetic probe on XuanLong-50 spherical torus

Wang

Lun²,

Bo³

et al. 2023

Plasma Sci. Technol.

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A high-frequency magnetic probe is designed and developed on the XuanLong-50 (EXL-50) spherical torus to measure high-frequency magnetic field fluctuation. The magnetic loop, radio filters, radio-frequency (RF) limiter, and data acquisition system of the probe are comprehensively examined. The fluctuation data from the EXL-50 plasma are analyzed in the time–frequency domain using fast Fourier transforms. Moreover, distinct high-frequency instabilities are detected using this diagnostic system. In particular, significant frequency chirping is observed, which is consistent with the bump-on-tail drive instability predicted using the Berk–Breizman model.

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Development of the ion cyclotron emission diagnostic on the HL-2A tokamak

Cited by 5 publications

References 29 publications

Identification of core ion cyclotron instabilities on HL-2A tokamak

Identification of core ion cyclotron instabilities on HL-2A tokamak

Predicting ion cyclotron emission from neutral beam heated plasmas in Wendelstein7-X stellarator

Radio-frequency measurements of energetic-electron-driven emissions using high-frequency magnetic probe on XuanLong-50 spherical torus

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