Impurity pump-out at the two-ion hybrid resonance during ICRF experiments in TFR tokamak plasmas

A heavy impurity (argon) is efficiently pumped out of a two-ion-component tokamak plasma during ICRF experiments in the mode conversion regime. This is achieved by choosing the plasma isotopic composition such that the two-ion hybrid layer location coincides with the position of the cyclotron frequency second harmonic of one of the argon ions.