Lower hybrid oscillating two-stream instability in a plasma with magnetic shear

Abstract

Magnetic shear is found to have a strong effect on the propagation characteristics of the lower hybrid parametric daughter waves but no significant effect on the pump wave. The analysis of the OTS instability shows that the convective damping introduced by magnetic shear acts on a distance L~ H{mjm i )^, where H is the magnetic shear scale length. There are two regimes for the convective damping, depending on the wavelength of the parametric daughter waves. For small wavelengths the growth rates are linear functions of (kL)- 1 . For large wavelengths the growth rates are exponentially decreasing functions of (kL)-\

Parametric processes in magnetically confined CTR plasmas

“…Since these modes exist only for co 0 /to LH <2, parametric decay and heating would again tend to occur in the interior of the plasma column (assuming the incident frequency was chosen appropriately). Similar calculations have been done for the purely growing mode (OTSI) by Wersinger et al [44], who obtained the following threshold: 2 (49) which is similar to that of Eq. (47).…”