TETRA Observation of Gamma Rays at Ground Level Associated with Nearby Thunderstorms

Abstract

Terrestrial Gamma ray Flashes (TGFs) -- very short, intense bursts of electrons, positrons, and energetic photons originating from terrestrial thunderstorms -- have been detected with satellite instruments. TETRA, an array of NaI(Tl) scintillators at Louisiana State University, has now been used to detect similar bursts of 50 keV to over 2 MeV gamma rays at ground level. After 2.6 years of observation, twenty-four events with durations 0.02- 4.2 msec have been detected associated with nearby lightning, three of them coincident events observed by detectors separated by ~1000 m. Nine of the events occurred within 6 msec and 3 miles of negative polarity cloud-to-ground lightning strokes with measured currents in excess of 20 kA. The events reported here constitute the first catalog of TGFs observed at ground level in close proximity to the acceleration site.

To be published in Journal of Geophysical Research: Space Phys. 118, 1

References in corpus (1)

• Gamma-Ray Localization of Terrestrial Gamma-Ray Flashes

Cited by in corpus (8)

• Experimental study on hard X-rays emitted from metre-scale negative discharges in air
• Observations of the Origin of Downward Terrestrial Gamma-Ray Flashes
• Measurement of the Electrical Properties of a Thundercloud Through Muon Imaging by the GRAPES-3 Experiment
• Characterizing upward lightning with and without a terrestrial gamma-ray flash
• Gamma Ray Flashes Produced by Lightning Observed at Ground Level by TETRA-II
• First High-speed Video Camera Observations of a Lightning Flash Associated with a Downward Terrestrial Gamma-ray Flash
• Gamma-rays Associated with Nearby Thunderstorms at Ground Level
• Dependence of the estimated electric potential in thunderstorms observed at GRAPES-3 on the hadronic interaction generators used in simulations