Edge Ion Heating and Parametric Decay During Injection of Ion Cyclotron Resonance Frequency Power on the Alcator C-Mod Tokamak

Download or read book Edge Ion Heating and Parametric Decay During Injection of Ion Cyclotron Resonance Frequency Power on the Alcator C-Mod Tokamak written by Jon Christian Rost and published by . This book was released on 2001 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A population of suprathermal ions has been observed in the scrape-off layer during injection of power in the ion cyclotron frequency range on the Alcator C-Mod tokamak. These ions generated energetic neutrals measured with a charge-exchange neutral particle analyzer. In the hydrogen minority heating regime, fast particles were generated only when the injected power was above 500kW. Fast particles were observed at a low level of injected power when the frequency was a multiple of the ion cyclotron frequency in the scrape-off layer. The power deposited in the edge was always less than a few percent of the injected power and did not increase impurity levels. The theoretical threshold of parametric decay instabilities for decay of the pump wave in the antenna near field into an ion Bernstein wave and an ion cyclotron quasimode matches the observed threshold for fast ion production under a variety of conditions.