ANALYSIS OF ELECTRON CYCLOTRON EMISSION FROM NON-THERMAL DISCHARGES IN THE ASDEX TOKAMAK
Results of electron cyclotron emission (ECE) measurements during low-density non-thermal ASDEX tokamak operation are presented. Particular attention is given to the transition between the thermal plasma state, where the electron velocity distribution is Maxwellian, and the non-thermal state, where the distribution function may be treated as a superposition of low and high energy components. The study is aided by the simultaneous use of two complementary ECE diagnostics, a rapid scan Michelson interferometer for measurement of the entire ECE spectrum and a four-channel polychromator for registration of time- resolved intensities at different wavelengths. Numerical simulations confirm the two-component description of the non-thermal distribution and provide estimates of the population and energy of the high energy part. By comparing X-mode and O-mode radiation, additional information regarding the optical depth of the low energy component is obtained.
Bibliographic Reference: NUCLEAR FUSION, VOL. 24 (1984), NO. 3. PP. 297-304
Record Number: 1989122106400 / Last updated on: 1987-01-01
Available languages: en