Demonstration of Electron-Bernstein-Wave Heating in a Tokamak via O-X-B Double-Mode Conversion
نویسندگان
چکیده
The first demonstration of electron-Bernstein-wave heating by double-mode conversion from the O to the X mode in an overdense H-mode tokamak plasma has been achieved in the Tokamak à Configuration Variable device. This technique overcomes the upper density limit experienced by conventional microwave heating. The sensitive dependence of the O-X mode conversion on the microwave launching direction has been verified experimentally, and localized power deposition consistent with theoretical predictions has been observed at densities well above the conventional cutoff.
منابع مشابه
گرم کردن پلاسما با امواج برنشتاین الکترونی از طریق واگردانی امواج عادی و فراعادی درلایه UHR
Magnetically confined plasma can be heated with high power microwave sources. In spherical torus the electron plasma frequency exeeds the electron cyclotron frequency (EC) and, as a consequence, electromagnetic waves at fundamental and low harmonic EC cannot propagate within the plasma. In contrast, electron Bernstein waves (EBWs) readily propagate in spherical torus plasma and are absorbed str...
متن کاملElectron Bernstein Wave Heating and Emission in the TCV Tokamak
Electron cyclotron heating of high density plasmas is limited due to so-called wave cut-offs. The double mode conversion scheme from O-mode to X-mode and finally to Bernstein mode O-X-B offers the possibility to overcome this limit [1]-[4]. At a particular launching angle, an O-mode wave converts to X-mode at the plasma cut-off. The power transmission function T from Oto X-mode was derived in [...
متن کاملHeating by an electron Bernstein wave in a spherical tokamak plasma via mode conversion.
The first successful high power heating of a high dielectric constant spherical tokamak plasma by an electron Bernstein wave (EBW) is reported. An EBW was excited by mode conversion (MC) of an mode cyclotron wave injected from the low magnetic field side of the TST-2 spherical tokamak. Evidence of electron heating was observed as increases in the stored energy and soft x-ray emission. The incre...
متن کاملInvestigation of Electron Bernstein Wave ( EBW ) Coupling and its Critical Dependence on EBW Collisional Loss in High - β , H - Mode ST Plasmas
In conventional aspect-ratio tokamaks, electron cyclotron (EC) waves can provide local heating and current drive. However, the high-β spherical tokamak (ST) plasma conditions cut off propagation of EC waves. The electron Bernstein wave (EBW) does not experience a density cut off and is strongly absorbed and emitted at the EC harmonics, allowing EBWCD to be used in STs for current profile contro...
متن کاملIon Cyclotron Range of Frequencies Mode Conversion Electron Heating in Deuterium-Hydrogen Plasmas in the Alcator C-Mod Tokamak
Localized direct electron heating by mode-converted ion cyclotron range of frequencies (ICRF) waves in D(H) tokamak plasmas has been clearly observed for the first time in Alcator C-Mod. Both onand off-axis (high field side) mode conversion electron heating (MCEH) have been observed. The MCEH profile was obtained from a break in slope analysis of electron temperature signals in the presence of ...
متن کامل