High‐Speed Video Observation of a Dart Leader Producing X‐rays

Autor: Hamid K. Rassoul, Marcelo M. F. Saba, Vernon Cooray, Carina Schumann, E. T. Cuadros, Amanda R. de Paiva, Marco A. S. Ferro, D. S. F. Medeiros, P. B. Lauria, D. M. Custódio, Pasan Hettiarachchi, Amitabh Nag
Rok vydání: 2019
Předmět:
Zdroj: Journal of Geophysical Research: Space Physics. 124:10564-10570
ISSN: 2169-9402
2169-9380
DOI: 10.1029/2019ja027247
Popis: This work presents the first simultaneous X-ray measurement and high-speed video observation of the propagation of a lightning leader producing X-rays. As a result, the three-dimensional leader distance from the X-ray measurement and, for the first time, the conditions of the preexisting channel during the leader propagation were observed. Although four leaders in this seven-stroke flash followed the same path to ground, X-rays were only observed during the leader before the return stroke with the highest peak current. The fact that the other three leaders following the same path to ground did not produce detectable X-rays confirms the hypothesis that leader line charge density is an important factor that determines X-ray production. The fact that X-rays was recorded only when the leader tip was at a certain portion of the lightning channel confirms that the orientation of the leader plays an important role in the detection of X-rays.
Databáze: OpenAIRE