EFDA-JET-PR(11)51

Flux and Spectra of Fast Charge- Exchange Atoms Measured by Natural Diamond Detector at JET Tokamak

To study the evolution of the distribution function of fast atoms in a real and kinetic spaces under different scenarios of additional plasma heating (injection of neutrals and ion cyclotron heating) in addition to multi-channel neutral particle analyzer a compact fast corpuscular spectrometer with a natural diamond detector was introduced at JET Tokamak. The new digital spectrometric tract at peak load allows spectrometer to reach a value 107 registrations per second. Established in the equatorial pipe of JET tokamak the diamond detector provides spectrometry of neutral particles in the energy range 70­5000keV. Flux of the charge-exchange atoms were observed both during simultaneous operation of the Ion-Cyclotron Resonant Heating (ICRH) and Neutral Beam Injection (NBI), and during only ICRH heating. The flux dynamics and spectra of the deuterium atoms with energy above 70keV in the experiments with a combined additional plasma heating are presented. The formation of a group of fast minority ions in the plasma accelerated by ICRH at the fundamental frequency, as well as the beam injected ions additionally accelerated by the ICRH through the mechanism at the second harmonic were observed.
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EFDP11051 653.88 Kb