Compton Camera Imaging of a Gamma‐Ray Glow From a Thunderstorm

Abstract

Gamma‐ray glows associated with thunderclouds have been observed since the 1980s, however it remains unclear how, and at which thunderstorms gamma‐ray glows are generated in dense atmospheres. In this study, we report the first Compton camera imaging of a gamma‐ray glow from a winter thundercloud. On 14 January 2022, using two identical Bi4Ge3O12 scintillators in energy range of 0.05–5 MeV, we detected two gamma‐ray glows lasting ∼4 min in a mountain area 25 km from the Japan Sea and 410 m above sea level. The same events were also observed by the Compton camera, where the first glow we observed suggested statistically significant (4.0 and 5.9 σ level) signals of two enhanced concentrations in gamma‐ray photon images in a range of 0.15–1.5 MeV. These concentrations were most clearly observed in a time window of Δt = 50 s around the peak intensity of the gamma‐ray glow.

Citizen Science Observation of a Gamma‐Ray Glow Associated With the Initiation of a Lightning Flash

“…The project summary will be reported in subsequent papers. In FY2021 only, we also conducted optical camera and gamma‐ray Compton camera imaging (Kataoka et al., 2013; Kuriyama et al., 2022; Omata et al., 2020) from a high‐rise window of a hotel in Kanazawa.…”

Citizen science "Thundercloud Project" -- multi-point radiation measurements of gamma-ray glows from accelerated electrons in thunderstorms

“…Abrupt termination of a gamma-ray glow associated with lightning discharges has also been observed, which is interpreted to be the disappearance of the electric field in thunderclouds due to the discharge [6,9,10]. Recently, there has been also research on meteorological conditions for gamma-ray glows [11,12], theoretical modeling [13][14][15], and a new imaging radiation detector [16]. During our observations of gamma-ray glows, we also discovered that terrestrial gamma-ray flashes (TGFs) produced by lightning discharges can cause photoneutron reactions in the atmosphere [10,[17][18][19][20], emitting neutrons and positrons into the atmosphere.…”