Plasma maser effect in magnetosphere plasma associated with MHD turbulence

The interaction of an ion acoustic wave with a kinetic Alfven wave is considered through the plasma maser effect. The plasma maser effect as an energy upconversion mode coupling process, is found to be effective in drawing energy from low frequency MHD turbulence in the resonant mode to the non-resonant ion acoustic wave turbulence in the magnetosphere plasma near the Earth's foreshock region. The calculated growth rate for the ion acoustic wave shows that one of the dominant turbulences in the region of the Earth's foreshock is excited as it draws energy from MHD turbulence through the plasma maser effect. (C) 1997 Published by Elsevier Science Ltd. All rights reserved.