Plasma interface of the EC waves to the LHD peripheral region
- National Institute for Fusion Science, Toki, 509-5292 (Japan)
- Grad. School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561 (Japan)
In order to realize an efficient ECRH and also to reduce stray radiation due to non-absorbed power during ECRH, it is necessary to excite a wave that is absorbed well near the electron cyclotron resonance. In the normal fusion magnetic field confinement machine and in the electron cyclotron frequency range, WKB approximation is valid almost all the way from antenna to the absorption region due to the large scale-length of the plasma density λ{sub n} and the magnetic shear τ{sub s} as compared with the local wavelength λ{sub 0}. In these situation, it is well known that the O/X mode propagates as O/X mode if τ{sub s} ≫ λ{sub 0}. Even in these situation, if τ{sub s} and λ{sub n} are comparable and |1/λ{sub O}−1/λ{sub X}|τ{sub s} ≪ 1, there still remains the question from where ”X” - or ”O” - mode become ”X” - or ”O” mode at the peripheral region. In order to simulate this situation, one dimensional full wave calculation code which solve electromagnetic wave equation under arbitrary magnetic field configuration and arbitrary density profile for a given polarization state are developed and incorporated in the upgraded ray tracing code LHDGauss. It is tried to find the density and shear scale lengths region where the mode mixing effect is not negligible.
- OSTI ID:
- 22496229
- Journal Information:
- AIP Conference Proceedings, Vol. 1689, Issue 1; Conference: 21. topical conference on radio frequency power in plasmas, Lake Arrowhead, CA (United States), 27-29 Apr 2015; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mode Conversion of Langmuir to Electromagnetic Waves with Parallel Inhomogeneity in the Solar Wind and the Corona
Advances in physics and applications of 3D magnetic perturbations on the J-TEXT tokamak
Related Subjects
GENERAL PHYSICS
ABSORPTION
ANTENNAS
COMPARATIVE EVALUATIONS
CONFINEMENT
CYCLOTRON FREQUENCY
DENSITY
ECR HEATING
ELECTROMAGNETIC RADIATION
ELECTRON CYCLOTRON-RESONANCE
ELECTRONS
INTERFACES
LENGTH
LHD DEVICE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
ONE-DIMENSIONAL CALCULATIONS
PLASMA DENSITY
SHEAR
STRAY RADIATION
WKB APPROXIMATION