Premium
Laboratory Measurements of X‐Ray Emissions From Centimeter‐Long Streamer Corona Discharges
Author(s) -
da Silva C. L.,
Millan R. M.,
McGaw D. G.,
Yu C. T.,
Putter A. S.,
LaBelle J.,
Dwyer J.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl075262
Subject(s) - physics , bremsstrahlung , electron , radiation , plasma , anode , corona (planetary geology) , astrophysics , atomic physics , optics , nuclear physics , astrobiology , venus , electrode , quantum mechanics
We provide extensive evidence that runaway electron acceleration and subsequent bremsstrahlung X‐ray emission are a common feature in negative electrical discharges with voltages as low as 100 kV, indicating that all negative lightning could potentially produce runaway electrons. Centimeter long streamer corona discharges produce bursts of X‐ray radiation, emitted by a source highly compact in space and time, leading to photon pileup. Median photon burst energies vary between 33 and 96 keV in 100 kV discharges. Statistical analysis of 5,000+ discharges shows that X‐rays are observed in as many as 60% of the triggers, depending on the configuration. X‐ray detection is more frequent when streamers are not followed by a spark, the detector is oriented perpendicular to the gap, and a thicker anode is used. In an 8‐cm‐long gap, X‐rays are produced when runaway electrons hit the anode, and the electron acceleration is not necessarily correlated with streamer collisions.