Energy Analysis of ECRH-Induced End-Loss Warm Electrons in a Tandem Mirror

抄録

The amount of an end-loss flux of warm electrons and its energy spectrum are studied by using an electrostatic energy analyser over a wide range of energy up to 10 keV in the GAMMA 10 tandem mirror. The outgoing electron flux is found to be much larger than the associated ion flux during the strong end-loss plugging under the fundamental electron cyclotron resonance heating. The observed energy spectrum reveals a high-energy tail component (T_eH∼3 keV) in addition to the already reported bulk warm component (T_eL∼700 eV). The new spectrum is successfully applied to evaluate the secondary electron flux from end plates so as to account for the charge balance of the net flux of electrons and the ion flux on the floating plates.