Optimization Study of ICRF Hydrogen Minority Heating in a Deuterium Plasma of EAST

Zhang, Xinjun; Fangwei, Yao

doi:10.1088/1009-0630/17/6/03

Cited by 4 publications

(4 citation statements)

References 14 publications

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“…This is consistent with the results in figure 7(b) in [24]; in the paper the perpendicular temperature is analyzed around 50 keV with 1 MW ICRF power. However, as shown in figure 2 of [24], the deposited ICRF power density in the peripheral is relatively small compared to the middle region. Here a simplification of the same effective perpendicular temperature in the whole resonance layer is adopted.…”

Section: Simulation Parameterssupporting

confidence: 91%

“…The y T ( ) is a constant, which is chosen to be 8 keV, corresponding to the perpendicular temperature 48 keV. This is consistent with the results in figure 7(b) in [24]; in the paper the perpendicular temperature is analyzed around 50 keV with 1 MW ICRF power. However, as shown in figure 2 of [24], the deposited ICRF power density in the peripheral is relatively small compared to the middle region.…”

Section: Simulation Parameterssupporting

confidence: 71%

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Numerical study on the loss of fast ions produced by minority ion cyclotron resonance heating in EAST

Zhang

Xiang

2021

Plasma Sci. Technol.

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The classical prompt loss of fast ions produced by minority ion cyclotron resonance heating (ICRH) is studied by a guiding center orbit following code in the Experimental Advanced Superconducting Tokamak (EAST). It is found that the loss of fast ions produced by ICRH mainly appears in both ends of the resonance layer, while the loss of fast ions in the middle resonance layer is very small. The dominant fast loss comes from trapped ions, rather than from passing ions. Controlling the location of resonance layer at the plasma core may be more beneficial to the EAST tokamak ICRH. In addition, the loss distribution of fast ions is studied. The results show that the fast ions are mainly lost near the midplane in the poloidal direction, but almost uniformly in the toroidal direction. Moreover, we investigate the dependence of fast ion loss on the ICRH power. The simulation results show that the loss fraction of fast ions in both ends of the resonance region increases with the ion cyclotron range of frequencies (ICRF) power, but barely affects the loss of fast ions in the middle region.

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Section: Simulation Parameterssupporting

confidence: 91%

Section: Simulation Parameterssupporting

confidence: 71%

Numerical study on the loss of fast ions produced by minority ion cyclotron resonance heating in EAST

Zhang

Xiang

2021

Plasma Sci. Technol.

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“…Magnetic tilt angle is θ=7° [37]. In this figure, as well as all the simulations provided in this section, we use a plasma composed of 95% D and 5% H, which is the typical compositions used in the hydrogen minority heating experiments [24,38]. In addition, the following TS like parameters are taken: the magnetic field intensity B 0 scales as 1/R a , with R a the major radius axis.…”

Section: Investigation Of the Role Of The Fast Wave On Rf Sheath Exci...mentioning

confidence: 99%

Modelling of radio frequency sheath and fast wave coupling on the realistic ion cyclotron resonant antenna surroundings and the outer wall

Lu¹,

Colas²,

Jacquot³

et al. 2018

Plasma Phys. Control. Fusion

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In order to model the sheath rectification in a realistic geometry over the size of Ion Cyclotron Resonant Heating (ICRH) antennas, the Self-consistent Sheaths and Waves for ICH (SSWICH) code couples self-consistently the RF wave propagation and the DC SOL biasing via non-linear RF and DC sheath boundary conditions (SBCs) applied at plasma/wall interfaces. A first version of SSWICH had 2D (toroidal and radial) geometry, rectangular walls either normal or parallel to the confinement magnetic field B0 and only included the evanescent slow wave (SW) excited parasitically by the ICRH antenna. The main wave for plasma heating, the fast wave (FW) plays no role on the sheath excitation in this version. A new version of the code, 2D SSWICH-Full Wave, was developed based on the COMSOL software, to accommodate full RF field polarization and shaped walls tilted with respect to B0. SSWICH-Full Wave simulations have shown the mode conversion of FW into SW occurring at the sharp corners where the boundary shape varies rapidly. It has also evidenced "far-field" sheath oscillations appearing at the shaped walls with a relatively long magnetic connection length to the antenna, that are only accessible to the propagating FW. Joint simulation, conducted by SSWICH-Full Wave within a multi-2D approach excited using the 3D wave coupling code (RAPLICASOL), has recovered the double-hump poloidal structure measured in the experimental temperature and potential maps when only the SW is modelled. The FW contribution on the potential poloidal structure seems to be affected by the 3D effects, which was ignored in the current stage. Finally, SSWICH-Full Wave simulation revealed the left-right asymmetry that has been observed extensively in the unbalanced strap feeding experiment s , suggesting that the spatial proximity effects in RF sheath excitation, studied for SW only previously, is st ill important in the vicinity of the wave launcher under full wave polarizations.

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“…Although the FILDs cannot identify which ion type is present, they can provide information on fast ion energy and pitch angle, thus providing the mechanism of the fast ion energy source. Since FILDs detect the fast ion loss in localized regions, the measurement information used to demonstrate the underlying physics is insufficient, and thus a reliable theoretical simulation model is needed to describe the energetic ions and the corresponding effects [11]. The simulation of the realistic FILDs signal, the specific geometry of the machine, and the background magnetic field can provide us with a useful tool to interpret the measured data and optimize the detector position, and thus gain a better understanding of the fast ion generation mechanisms and transport processes [12].…”

Section: Introductionmentioning

confidence: 99%

3D simulation of orbit loss and heat load on limiters of ICRF-NBI synergy induced fast ions on EAST

Zheng

Zhang

et al. 2023

Nucl. Fusion

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Fast ions synergy induced by ion-cyclotron range of frequency (ICRF) and neutral beam injection (NBI) are of interest not only because of their advantage of heating the plasma and drive currents, but also because of their disadvantage of damaging plasma surface components and driving MHD instabilities. In this paper, we calculate the fast ion loss and the deposition distribution of the lost particles on the limiters in EAST under the synergistic effect of the ripple field and collisions with the full-orbit-following simulation program ISSDE for the first time. The previous models to study the NBI fast ion loss by the action of ICRF are relatively simple and consider fewer influencing factors. Most studies on fast ion loss have used toroidal uniform boundaries. In this work, we consider the distribution of ICRF-NBI synergy induced fast ions with different minority H concentrations. After setting the limiter boundary, we consider the prompt fast ion loss caused by the equilibrium field and the fast ion loss caused by the ripple field and collision. Under the action of minority-ion ICRH, the NBI fast ion distribution function has spread in the high-energy part, especially for the minority H concentration of 1\%, and the fast ions show each anisotropic distribution near the resonance band on the poloidal dimension. The synergistic loss caused by the ripple field and collision will first be greater than the loss caused by either factor, and then reach a final loss fraction of 3.8\%. The heat load power density of the lost fast ions on different limiters is not uniform, as well as on each limiter, which is related to the distance from the limiter to the plasma, the relative position between the limiters and the parallel direction of most fast ions. Once the study of ICRF-NBI synergy induced fast ion loss caused by the action of ripple and collision has been done, we can do optimization in a targeted manner. Such as adding ferromagnetic inserts to reduce the ripple loss and optimizing the limiters’ position to reduce or control the generation of impurities.

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Optimization Study of ICRF Hydrogen Minority Heating in a Deuterium Plasma of EAST

Cited by 4 publications

References 14 publications

Numerical study on the loss of fast ions produced by minority ion cyclotron resonance heating in EAST

Numerical study on the loss of fast ions produced by minority ion cyclotron resonance heating in EAST

Modelling of radio frequency sheath and fast wave coupling on the realistic ion cyclotron resonant antenna surroundings and the outer wall

3D simulation of orbit loss and heat load on limiters of ICRF-NBI synergy induced fast ions on EAST

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