Invited paper: Parametric instabilities in the tokamak edge plasma in the ion cyclotron heating regimes

Abstract

Parametric instabilities in the scrape-off layer (SOL) of tokamak plasmas are studied in the presence of ICRF and/or IBW RF fields. Growth rates and typical threshold RF fields are deduced for multi-ion species plasmas for pump frequencies in the vicinity of the first few ion cyclotron harmonics. Decay instabilities into ion Bernstein waves and quasi-modes are predicted to occur. Such decay waves may lead to edge heating and impurity generation.