Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1002/2016GL072216 |
Electron acceleration during streamer collisions in air | |
Kohn, Christoph; Chanrion, Olivier; Neubert, Torsten | |
2017-03-16 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS |
ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2017 |
卷号 | 44期号:5 |
文章类型 | Article |
语种 | 英语 |
国家 | Denmark |
英文摘要 | High-voltage laboratory experiments show that discharges in air, generated over a gap of one meter with maximal voltage of 1MV, may produce X-rays with photon energies up to 1MeV. It has been suggested that the photons are bremsstrahlung from electrons accelerated by the impulsive, enhanced field during collisions of negative and a positive streamers. To explore this process, we have conducted the first self-consistent particle simulations of streamer encounters. Our simulation model is a 2-D, cylindrically symmetric, particle-in-cell code tracing the electron dynamics and solving the space charge fields, with a Monte Carlo scheme accounting for collisions and ionization. We present the electron density, the electric field, and the velocity distribution as functions of space and time. Assuming a background electric field 1.5 times the breakdown field, we find that the electron density reaches 210(21)m(-3), the size of the encounter region is approximate to 310(-12)m(3) and that the field enhances to approximate to 9 times the breakdown field during approximate to 10(-11)s. We further find that the radial component becomes comparable to the parallel component, which together with angular scattering leads to an almost isotropic distribution of electrons. This is consistent with laboratory observations that X-rays are emitted isotropically. However, the maximum energy of electrons reached in the simulation is approximate to 600eV, which is well below the energies required to explain observations. The reason is that the encounter region is small in size and duration. For the photon energies observed, the field must be enhanced in a larger region and/or for a longer time. |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000398183700063 |
WOS关键词 | GAMMA-RAY FLASHES ; BREMSSTRAHLUNG ; FIELD |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/28804 |
专题 | 气候变化 |
作者单位 | Tech Univ Denmark, Natl Space Inst, DTU Space, Kongens Lyngby, Denmark |
推荐引用方式 GB/T 7714 | Kohn, Christoph,Chanrion, Olivier,Neubert, Torsten. Electron acceleration during streamer collisions in air[J]. GEOPHYSICAL RESEARCH LETTERS,2017,44(5). |
APA | Kohn, Christoph,Chanrion, Olivier,&Neubert, Torsten.(2017).Electron acceleration during streamer collisions in air.GEOPHYSICAL RESEARCH LETTERS,44(5). |
MLA | Kohn, Christoph,et al."Electron acceleration during streamer collisions in air".GEOPHYSICAL RESEARCH LETTERS 44.5(2017). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论