Parametric coupling of low frequency whistler to Alfven wave in a plasma
- Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)
- Department of Applied Sciences and Humanities, Jamia Millia Islamia, New Delhi 110025 (India)
The parametric decay of a large amplitude electromagnetic wave in the ion cyclotron range of frequency into a compressional Alfven wave and an electromagnetic sideband wave in a magnetized plasma is investigated. The pump wave propagates in the direction of ambient magnetic field whereas the decay waves propagate at oblique angles. When the pump wave is left circularly polarized the decay is not permitted kinematically as the momentum of pump photon always exceeds the sum of momenta of the decay wave photons. For the right circularly polarized whistler mode pump the decay is permitted with sideband nearly right circularly polarized. The density perturbation associated with the Alfven wave couples with the pump driven oscillatory velocities of ions and electrons to produce a current driving the sideband. The sideband and the pump exert pondermotive force on ions and electrons that drive the Alfven wave. The frequency and growth rate of the Alfven wave increase with the normalized pump frequency. The threshold power density, determined by the collisional damping rates of the decay waves is rather modest.
- OSTI ID:
- 21371314
- Journal Information:
- Physics of Plasmas, Vol. 16, Issue 12; Other Information: DOI: 10.1063/1.3270109; (c) 2009 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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