Macroscopic Stability Formalism for a Tandem Mirror with RF Ponderomotive Force Effects

摘要

The ponderomotive force arising from the rf field in the ion cyclotron frequency range is investigated and its effects on the dispersion relation for the stability of low mode number modes in the tandem mirror analyzed. It is shown that the ponderomotive force from the E/sub L/ (left-circularly polarized) wave at omega = omega /sub ci/ is zero rather than infinity due to the finite temperature effects. Also, the thermal effects on the force from the E/sub R/ and E/sub z/ wave are calculated. The results show that thermal effects on the force are so crucial that they change the sign of the force due to the E/sub R/ and E/sub z/ waves in the Phaedrus tandem mirror parameter range. This may explain the Phaedrus experimental results which are that the plasma is stable for omega > omega /sub ci/, but becomes unstable for omega < omega /sub ci/. The dispersion relation for the macroscopic stability of Phaedrus type plasmas is derived. Also, the m = 1 rigid mode of the plasma is analyzed, including the effects due to finite Larmor radius (FLR) and an ambipolar potential. (ERA citation 11:028993)