EFFECT OF FINITE MAGNETIC-MOMENT ON THRESHOLD AMPLITUDE OF ELECTROSTATIC-WAVES IN NONLINEAR DYNAMICS

An ensemble of electrostatic waves propagating obliquely to the extern al uniform magnetic field accelerates the plasma electrons, giving ris e to a mechanical energy in terms of finite magnetic moment (mu). In n onlinear analysis, this magnetic moment modifies the resonances among the harmonics (l) and the overlapping parameter (K) leading to stochas ticity. It is shown that the threshold amplitude (phi(k)) of electrost atic waves at the onset of chaos increases slowly for l=0 harmonics an d sharply for higher harmonics (l greater than or equal to 1), owing t o the effect of magnetic moment. A sharp decrease of threshold amplitu de with wave vector (k) pertaining to the ensemble of waves for higher harmonics (l greater than or equal to 1) is also delineated. The find ings may have astrophysical and cosmological signatures in the high en ergy particle regimes. (C) 1998 American Institute of Physics.