DOI: 10.1029/2018JD028646
Scopus记录号: 2-s2.0-85050383431
论文题名: X-ray Emissions in a Multiscale Fluid Model of a Streamer Discharge
作者: Lehtinen N.G. ; Østgaard N.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 13 起始页码: 6935
结束页码: 6953
语种: 英语
英文关键词: adaptive mesh refinement
; electric discharge model
; runaway electrons
; streamer collision
; terrestrial gamma ray flash
Scopus关键词: atmospheric modeling
; avalanche
; collision
; electric field
; electron
; emission
; gamma radiation
; numerical model
; simulation
; X-ray
英文摘要: We use a three-specie fluid model of electric discharge in air to simulate streamer evolution from the avalanche-to-streamer transition to the collision of opposite-polarity streamers. We estimate the upper limit on the production of thermal runaway electrons, which is dominant during the second of these processes. More thermal runaways are produced if the ionization due to natural background and photoionization is reduced, due to possibility of creation of higher electric fields at streamer tips. The test-particle simulation shows, however, that these thermal runaway electrons have insufficient energies to become relativistic runaways. The simulations are done in constant uniform background fields of E0=4 and 6 MV/m. A simulation was also performed in E0=2 MV/m after formation of streamers in 4-MV/m field, in order to approximate the average background field created by ∼1-MV voltage over a ∼1-m electrode gap used in laboratory spark experiments. We conclude that the used fluid model is insufficient to explain X-ray observations during such experiments. We discuss the possible role of mechanisms which were not included in this or previous modeling but may play the deciding role in the electron acceleration and X-ray production during a streamer collision. ©2018. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113520
Appears in Collections: 气候减缓与适应
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作者单位: Birkeland Centre for Space Science, University of Bergen, Bergen, Norway
Recommended Citation:
Lehtinen N.G.,Østgaard N.. X-ray Emissions in a Multiscale Fluid Model of a Streamer Discharge[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(13)