Measurement of the Magnetic Field in a Spherical Torus Plasma via Electron Bernstein Wave Emission Harmonic Overlap.

Jones, B. ; Taylor, G. ; Efthimion, P. C. ; Munsat, T.

Technical Information Center Oak Ridge Tennessee

关键词: Magnetic fields;    Harmonics;    Plasma(Physics);    Electron density;    Mode conversion;   

RP-ID  :  DE2004821517

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Measurement of the magnetic field in a spherical torus by observation of harmonic overlap frequencies in the electron Bernstein wave (EBW) spectrum has been previously suggested. EBW mode conversion to X-mode radiation has been studied in the Current Drive Experiment-Upgrade spherical torus, with emission measured at blackbody levels. Sharp transitions in the thermally emitted EBW spectrum have been observed for the first two harmonic overlaps. These transition frequencies are determined by the magnetic field and electron density at the mode conversion layer in accordance with hot-plasma wave theory. Prospects of extending this measurement to higher harmonics, necessary in order to determine the magnetic field profile, and high beta equilibria are discussed for this proposed magnetic field diagnostic.