Maser-beam instability of Bernstein waves

Abstract

The present study constitutes a continuation and improvement of the preceding work by Yoon et al. [J. Geophys. Res. 104, 19801 (1999)]. In the present discussion, an instability of Bernstein waves excited by a beam of energetic electrons is investigated. Special attention is paid to the regime where the ratio of plasma frequency, ωpe, to electron gyrofrequency, Ωe, is sufficiently higher than unity. An approximate but fairly accurate scheme is introduced to deal with the situation dictated by the condition, ωpe2/Ωe2≫1. The present investigation is motivated by the research in solar radiophysics. However, in this article the emphasis is placed on basic properties of the instability rather than its application.

Excitation of electron Bernstein waves by a gyrating relativistic electron beam in a plasma slab

“…1-10 Electron Bernstein waves [11][12][13][14][15][16][17][18] are a special kind of wave in these systems whose frequencies lie close to the harmonics of cyclotron frequency and wave numbers are greater than the inverse Larmor radius. 1-10 Electron Bernstein waves [11][12][13][14][15][16][17][18] are a special kind of wave in these systems whose frequencies lie close to the harmonics of cyclotron frequency and wave numbers are greater than the inverse Larmor radius.…”

Excitation of Bernstein waves by energetic pickup ions

“…In both areas, contemporary plasma physics plays fundamentally important roles. In several recent articles, the excitation of Bernstein waves in the solar corona (Yoon et al 1999;Ziebell et al 2000) and the energization of newly created ions near a flare site (Wang et al 2001) are discussed. In the former case, it is postulated that the excitation is mainly due to fast electrons streaming along the ambient magnetic field, and in the latter study the acceleration of ions is attributed to a pickup process by enhanced Alfvén waves in a reconnection layer.…”

“…Because Bernstein waves are propagating in directions perpendicular to an ambient magnetic field, usually these waves cannot be excited by particles that are moving along the background magnetic field. The works by Yoon et al (1999) and Ziebell et al (2000) make the point that a maser instability associated with a beam of fast electrons can occur. The theoretical analyses emphasize a resonant process that involves a relativistic effect.…”

Bernstein instability driven by thermal ring distribution

“…(2), 21 the Dorry-Guest-Harris (DGH) type of loss-cone distribution, 22,23 partially filled loss-cone models, 24,25 and the partial shell distribution. 26,27 Unlike these approaches, when the entire electron population possesses a non-Maxwellian feature, the real frequency and growth rate must be computed concomitantly, which is the focus of the remainder of this Brief Communication.…”