Simulation of ion cyclotron radiofrequency heating in EAST
LAN Yan1, YOU Qingliang fillmore2, CHENG Cheng 1
NI Guohua 1, M. Nagatsu3, MENG Yuedong 1
1 Institute of Plasma Physics, Chine Academy of Sciences, Hefei 230031, China
2 Hubei Rearch Institute of Chemistry, Wuhan 430074, China
3 Faculty of Engineering, Shizuoka University, Hamamatsu 432-8011, Japan球拍的拼音
Abstract：The ion cyclotron radiofrequency (ICRF) heating is a main auxiliary heating method in the Experimental Advanced Superconducting Tokamak (EAST). The ICRF system of EAST provides radiofrequencies from 30 MHz to 110 MHz and wave power of 3 MW. A full wave code TORIC has been ud to simulate veral traditional heating scenarios which can be carried out in EAST: D(H) heating, and D(3He) heating. By using TORIC, we predict the location of resonance layers of the heating scenarios and model f纸盒手工
or different heating motivations 连绵的意思in EAST ICRF experiments: ion heating (fundamental and harmonic) or electron heating (fast wave and mode conversion waves), on-axis heating or off-axis heating, high-field-side (HFS) heating or low-field-side (LFS) heating. And for an on-axis minority heating of 3He in D (3He) plasma, the impact of plasma density and temperature on heating effect has been studied in the EAST parameter ranges. 艾灸的副作用
Keywords：ICRF, TORIC, mode-conversion (MC), minority heating, poloidal modes, on-axis, off-axis, IBW, ICW.
PACS: 52.50.Qt
1. Introduction
The Experimental Advanced Superconducting Tokamak (EAST) is a non-circular advanced steady-state plasma experimental device with the main parameters: toroidal field Bo=3.5 T, major radius (Geometric) Ro=1.75 m, minor radius a=0.4 m, and plasma current Ip=1.0 MA. As well as Lower Hybrid Wave (LHW) heating and Neutral Beam Injec
tion (NBI) heating, the Ion Cyclotron Radiofrequency Heating (ICRH) is an important auxiliary heating method in EAST with the ICRF system which provides 30MHz-110MHz radiofrequencies and 3MW wave power launched into plasma [1].
教育漫画Usually for the ICRF heating regimes, becau the wavelength can be compared with the dimension of normal size Tokamaks (like EAST), ray-tracing code does not work [2]. So, for the simulation of ICRF physics in EAST, we should employ full wave codes [3-6] which solve Maxwellian equation (1) in the prence of a plasma and wave antenna:
(1)
TORIC [7] is a full wave code which solves wave equation (1) in arbitrary axisymmetric toroidal geometry bad on finite Larmor radius approximation [8]. The wave damping on the ions at the fundamental ion cyclotron frequencies and first harmonic ones can be described by TORIC code . And it can also describe Landau and transit time pumping damping on electrons by fast wave (FW), and the mode-conversion (MC) of the fast wave
to shorter wavelength ones such as the ion Bernstein wave (IBW) which keeps going to the high field side and the ion cyclotron wave (ICW) 裁判员宣誓词[9] which reflects to the low field side where the fast wave is launched. TORIC code has been benchmarked with other ICRF codes and experiments in Alcator C-mod and AUG, and proved to be a uful tool [10-15].
It employs poloidal and toroidal mode reprentation for the wave electric field.
(2)
where m and n are the poloidal and toroidal mode number respectively. Note that the poloidal modes are not of a local extent in within a flux surface and the coupling between poloidal modes due to toroidicity is very strong and can not be regarded as a perturbation, therefore, enough poloidal elements should be needed for the convergence of the reprentation (2) especially in the mode-conversion scenarios since the discontinuities at the mode-conversion layers require more terms to reprent [12-13].
2. D(H) Scenario in EAST Tokamak
2.1 TORIC convergence study of D (H) heating in EAST
For an EAST reference equilibrium (Figure.2), we study the convergence of power deposition with poloidal resolution for D (H) minority heating modeled by TORIC. We assume analytic profiles for particles’ density and temperature:
（3）
（4）
（5）
The subscripts ‘axis’ and ‘p’ mean the axis and the last clod magnetic surface respectively.
2.2. Modeling of D (H) heating in EAST
砂锅排骨
For the EAST reference equilibrium, the radiofrequency from 40MHz to 60MHz can locate the resonance layer of H (fundamental) as well as that of D (harmonic) in the plasma. (figure.4) The location of the mode coversion layer is determined by the concentration of the minority ion H then. Figure.5 (a), (b), (c) and (d) give the global power balance of D (H) heating scenarios for minority concentration range from 3% to 20% at the frequencies of 48 MHz (on-axis heating of ions), 45MHz, 43MHz,(LFS heating of ions) and 50MHz (HFS heating of ions) respectively.
