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Title: Self-consistent modeling of radio-frequency plasma generation in stellarators

A self-consistent model of radio-frequency (RF) plasma generation in stellarators in the ion cyclotron frequency range is described. The model includes equations for the particle and energy balance and boundary conditions for Maxwell’s equations. The equation of charged particle balance takes into account the influx of particles due to ionization and their loss via diffusion and convection. The equation of electron energy balance takes into account the RF heating power source, as well as energy losses due to the excitation and electron-impact ionization of gas atoms, energy exchange via Coulomb collisions, and plasma heat conduction. The deposited RF power is calculated by solving the boundary problem for Maxwell’s equations. When describing the dissipation of the energy of the RF field, collisional absorption and Landau damping are taken into account. At each time step, Maxwell’s equations are solved for the current profiles of the plasma density and plasma temperature. The calculations are performed for a cylindrical plasma. The plasma is assumed to be axisymmetric and homogeneous along the plasma column. The system of balance equations is solved using the Crank-Nicholson scheme. Maxwell’s equations are solved in a one-dimensional approximation by using the Fourier transformation along the azimuthal and longitudinal coordinates. Resultsmore » of simulations of RF plasma generation in the Uragan-2M stellarator by using a frame antenna operating at frequencies lower than the ion cyclotron frequency are presented. The calculations show that the slow wave generated by the antenna is efficiently absorbed at the periphery of the plasma column, due to which only a small fraction of the input power reaches the confinement region. As a result, the temperature on the axis of the plasma column remains low, whereas at the periphery it is substantially higher. This leads to strong absorption of the RF field at the periphery via the Landau mechanism.« less
Authors:
;  [1] ;  [2] ;  [1]
  1. National Academy of Sciences of Ukraine, National Science Center Kharkov Institute of Physics and Technology (Ukraine)
  2. Royal Military Academy, EURATOM-Belgian State Association, Laboratory for Plasma Physics (Belgium)
Publication Date:
OSTI Identifier:
22216068
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Physics Reports; Journal Volume: 39; Journal Issue: 11; Other Information: Copyright (c) 2013 Pleiades Publishing, Ltd.; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABSORPTION; ANTENNAS; AXIAL SYMMETRY; CONVECTION; CYCLOTRON FREQUENCY; CYLINDRICAL CONFIGURATION; ELECTRON TEMPERATURE; ELECTRONS; ENERGY BALANCE; ENERGY LOSSES; EQUATIONS; FOURIER TRANSFORMATION; ION TEMPERATURE; LANDAU DAMPING; ONE-DIMENSIONAL CALCULATIONS; PLASMA DENSITY; RADIOWAVE RADIATION; SIMULATION; STELLARATORS; THERMAL CONDUCTION