A 2D simulation study of Langmuir, whistler, and cyclotron maser instabilities induced by an electron ring-beam distribution

Abstract

Influence of wall impedance and self-fields on the cyclotron maser instability This paper presents a quasilinear analysis of the relativistic electron cyclotron maser instability in which the self-consistent set of equations governing the evolution of the particle distribution function and the energy spectra of unstable waves is numerically solved for parameters typical of the Earth's auroral zone plasma, taking into account both resonant and non-resonant diffusions. The results obtained show that only 0.1%0.2% of the particle energy is converted into wave energy by the loss cone instability, and also show that the saturation amplitude for the extraordinary mode increases in proportion to the ratio between electron cyclotron frequency and electron plasma frequency, in agreement with previous results obtained with numerical simulations. © 1997 American Institute of Physics. S1070-664X9704407-8

Highly structured electron anisotropy in collisionless reconnection exhausts

“…To assess the stability of the ring distribution, we have performed analysis using a PIC simulation in which electrons were initialized to a ring distribution like distribution 2 in Figure 2 with pe ∕Ω ce = 2 and with immobile ions similar to the simulation employed by Lee et al [2011]. We find the ring distribution to be unstable to whistler wave generation.…”

The effects of density inhomogeneities on the radio wave emission in electron beam plasmas

“…This was, perhaps, the reason why most of the previous studies of the ECMI were carried out with beam-to-background density ratios of the order of or even higher (see e.g. Pritchett 1984; Lee et al 2011; Zhou et al 2020). Second, different from most previous studies where an extended and homogeneous beam is pushed to repeatedly travel many times throughout the simulation domain because of the periodic boundary conditions, we allow only one pass of the localized beam through the simulation domain along the parallel, inhomogeneous direction (see details later).…”

“…For ECME, a positive gradient in the EVDF is needed in the direction perpendicular to the magnetic field, , e.g. in loss-cone (Benáček & Karlický 2017), ring (Pritchett 1984; Lee, Omura & Lee 2011), horseshoe (Bingham & Cairns 2000; Melrose & Wheatland 2016), cup-like (Büchner & Kuska 1996) or shell-shaped distribution functions. The corresponding ‘inverted’ population in the velocity space led to the early authors calling this cyclotron-resonance-related mechanism a ‘maser’ mechanism.…”

Generation of He+ and O+ EMIC waves by the bunch distribution of O+ ions associated with fast magnetosonic shocks in the magnetosphere

“…The total magnetic energy shows a growth rate of ω i /Ω H ≈ 0.016 and saturates around tΩ À1 H ¼ 460. In k || À k ⊥ spectrum, showing peak wave intensity in ω domain as a function of k || and k ⊥ [Lee et al, 2011], the quasi-perpendicular waves (k || ≈ 0.086Ω H /V A and k ⊥ ≈ 0.7 À 1.3Ω H /V A ) have the highest intensity. Two wave groups of moderate intensity with quasi-parallel propagation are found around k || = 0.07Ω H /V A and k || = 0.15Ω H /V A .…”