Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2018GL077788 |
High-Energy Emissions Induced by Air Density Fluctuations of Discharges | |
Kohn, C.; Chanrion, O.; Neubert, T. | |
2018-05-28 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS
![]() |
ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2018 |
卷号 | 45期号:10页码:5194-5203 |
文章类型 | Article |
语种 | 英语 |
国家 | Denmark |
英文摘要 | Bursts of X-rays and-rays are observed from lightning and laboratory sparks. They are bremsstrahlung from energetic electrons interacting with neutral air molecules, but it is still unclear how the electrons achieve the required energies. It has been proposed that the enhanced electric field of streamers, found in the corona of leader tips, may account for the acceleration; however, their efficiency is questioned because of the relatively low production rate found in simulations. Here we emphasize that streamers usually are simulated with the assumption of homogeneous gas, which may not be the case on the small temporal and spatial scales of discharges. Since the streamer properties strongly depend on the reduced electric field E/n, where n is the neutral number density, fluctuations may potentially have a significant effect. To explore what might be expected if the assumption of homogeneity is relaxed, we conducted simple numerical experiments based on simulations of streamers in a neutral gas with a radial gradient in the neutral density, assumed to be created, for instance, by a previous spark. We also studied the effects of background electron density from previous discharges. We find that X-radiation and gamma-radiation are enhanced when the on-axis air density is reduced by more than similar to 25%. Pre-ionization tends to reduce the streamer field and thereby the production rate of high-energy electrons; however, the reduction is modest. The simulations suggest that fluctuations in the neutral densities, on the temporal and spacial scales of streamers, may be important for electron acceleration and bremsstrahlung radiation. |
英文关键词 | air perturbations streamer modeling X-ray emission pre-ionization |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000435262000073 |
WOS关键词 | GAMMA-RAY FLASHES ; ELECTRIC-FIELD ; NEUTRAL DYNAMICS ; LIGHTNING LEADER ; PULSED CORONA ; SHOCK-WAVES ; X-RAY ; STREAMER ; SIMULATION ; MODEL |
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/26345 |
专题 | 气候变化 |
作者单位 | Tech Univ Denmark, Natl Space Inst DTU Space, Lyngby, Denmark |
推荐引用方式 GB/T 7714 | Kohn, C.,Chanrion, O.,Neubert, T.. High-Energy Emissions Induced by Air Density Fluctuations of Discharges[J]. GEOPHYSICAL RESEARCH LETTERS,2018,45(10):5194-5203. |
APA | Kohn, C.,Chanrion, O.,&Neubert, T..(2018).High-Energy Emissions Induced by Air Density Fluctuations of Discharges.GEOPHYSICAL RESEARCH LETTERS,45(10),5194-5203. |
MLA | Kohn, C.,et al."High-Energy Emissions Induced by Air Density Fluctuations of Discharges".GEOPHYSICAL RESEARCH LETTERS 45.10(2018):5194-5203. |
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