Bernstein wave in relativistic plasma with arbitrary energy anisotropy
Abstract
The Bernstein wave (BW) in a magnetized relativistic plasma is discussed in detail for a particular choice of distribution function1 that permits an exact analytical reduction of the dispersion relation for arbitrary energy anisotropy. The resulting dispersion relation is solved numerically in order to highlight the effect of energy anisotropy and the relativistic effects on the propagation characteristics of BW. The oscillatory character of the Bessel function appears due to the particular choice of the distribution function and thus changes the propagation characteristics significantly for short wavelengths (i.e., perpendicular wavelength is smaller than Larmour radius kρ>1 ). However, for longer wavelengths, these characteristics show a trend similar to the Maxwellian distribution. The dispersion relations for the non-relativistic and ultra-relativistic regimes are also obtained. The anisotropy provides a free energy to make the Bernstein wave unstable satisfying the threshold condition due to oscillatory character of the Bessel functions. Our result may prove useful for a wide range of applications e.g., for magnetized relativistic plasma environments such as astrophysical and space plasmas, laboratory plasmas with intense rf heating and for relativistic electron beams used for microwave generation. 1. P. H. Yoon and R.C. Davidson, Phys. Rev. A, 35, 2619 (1987).
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMSA43B2087B
- Keywords:
-
- 7500 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7800 SPACE PLASMA PHYSICS;
- 7829 SPACE PLASMA PHYSICS / Kinetic waves and instabilities