SOLITARY KINETIC ALFVEN WAVES WITH FINITE ION GYRORADIUS

A solitary kinetic Alfven wave (SKAW) with a finite ion gyroradius is obtained by using kinetic theory. It is found that the existence of SK AW depends not only on the parallel wave number but also on the perpen dicular wave number. In contrast to the results with cold ions, both t he super-Alfvenic and the sub-Alfvenic solitons exist in the density c ompressive region. The amplitude and the parallel propagation velocity of the solitons are found to be enhanced,while the width is narrowed due to the finite ion gyrodius effect. (C) 1998 American Institute of Physics. [S1070-664X(98)00609-0]