LOCAL TRANSIT-TIME DAMPING IN A MAGNETIC-FIELD, AND THE ARREST OF LOWER-HYBRID WAVE COLLAPSE

The transit-time power dissipated locally within a coherent wave packe t in the presence of ambient and induced magnetic fields is calculated analytically as a function of position via a perturbed-orbit approach , generalizing earlier results for unmagnetized interactions. The theo ry is used to investigate local damping in a nonlinearly-collapsing lo wer-hybrid (LH) wave packet, and hence to estimate the arrest scale of LH wave collapse in a thermal electron-ion plasma. It is shown that e ither electrons or ions can dominate damping, depending on the strengt h of the magnetic field and the electron and ion temperatures. (C) 199 6 American Institute of Physics.