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Title: X-ray Emission from Thunderstorms and Lightning

How lightning is initiated in the relatively low electric fields inside thunderclouds and how it can then propagate for tens of kilometers through virgin air are two of the great unsolved problems in more »the atmospheric sciences.  Until very recently it was believed that lightning was entirely a conventional discharge, involving only low-energy (a few eV) electrons.  This picture changed completely a few years ago with the discovery of intense x-ray emission from both natural cloud-to-ground lightning and rocket-triggered lightning.  This energetic emission cannot be produced by a conventional discharge, and so the presence of x-rays strongly implies that runaway breakdown plays a role in lightning processes.  During runaway breakdown, electrons are accelerated through air to nearly the speed of light by strong electric fields.  These runaway electrons then emit bremsstrahlung x-rays and gamma-rays during collisions with air.  Indeed, the x-ray and gamma-ray emission produced by runaway breakdown near the tops of thunderstorms is bright enough to be seen from outer space, 600 km away.  As a result, the physics used for decades to describe thunderstorm electrification and lightning discharges is incomplete and needs to be revisited. « less
Title: X-ray Emission from Thunderstorms and Lightning
Publication Date: 2009-07-08
OSTI Identifier: 987257
DOE Contract Number: AC02-07CH11359
Other Number(s): Other: 090708Dwyer
Resource Type: Multimedia
Specific Type: Multimedia Presentation
Resource Relation: Conference: Fermilab Colloquia, Fermi National Accelerator Laboratory (FNAL), Batvia, Illinois (United States), presented on July 08, 2009
Research Org: FNAL (Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States))
Sponsoring Org: USDOE Office of Science (SC)
Publisher: Fermilab Colloquia Online: 2000 to the Present Videos of Science Lecture and Presentations from the Colloquium Program at Fermi National Laboratory
Country of Publication: United States
Language: English
Run Time: 0:55:49
System Entry Date: 2016-01-27