Cross-Field Current Instabilities in Thin Ionization Layers and the Enhanced Aurora

Okuda, Jay R. Johnson and Hideo

Princeton University. Plasma Physics Laboratory.

关键词: Space Plasma Physics, Wave Interaction Particles, Wave Absorption;    Heating;    Ionization Space Plasma Physics, Wave Interaction Particles, Wave Absorption;    Electrostatics;    70 Plasma Physics And Fusion Technology;   

DOI  :  10.2172/959386
RP-ID  :  PPPL-4313
RP-ID  :  DE-ACO2-76CHO3073
RP-ID  :  959386

美国|英语

来源: UNT Digital Library

【 摘 要 】

Nearly half of the time, auroral displays exhibit thin, bright layers known as \enhanced aurora." There is a substantial body of evidence that connects these displays with thin, dense, heavy ion layers in the E-region. Based on the spectral characteristics of the enhanced layers, it is believed that they result when wave-particle interaction heats ambient electrons to energies at or just above the 17 eV ionization energy of N2. While there are several possible instabilities that could produce suprathermal electrons in thin layers, there has been no clear theoretical investigation which examines in detail how wave instabilities in the thin ionization layers could develop and produce the suprathermal electrons. We examine instabilities which would occur in thin, dense, heavy ion layers using extensive analytical analysis combined with particle simulations. We analyze a cross field current instability that is found to be strongly unstable in the heavy ion layers. Electrostatic simulations show that substantial heating of the ambient electrons occurs with energization at or above the N2 ionization energy.