Abstract
To identify the role of the gamma radiation from radon progenies in the long lasting thunderstorm ground enhancement (TGE) flux, a differential energy spectrum was measured with various spectrometers, including a precise NaI(Tl) spectrometer from ORTEC (FWHM at 0.6 MeV). Measurements demonstrate that radon progenies radiation significantly contribute to the winter enhancements in the energy range below 0.3–2 MeV. However, performed Monte Carlo simulations and observation of TGEs with plastic scintillators of various thickness and energy thresholds show that TGEs originate in intracloud electric fields. Recent registration of gamma glows by spectrometers located on board aircraft flying at 12–20 km altitude also confirms an “electric” nature of particle flux enhancements.
- Received 26 January 2019
DOI:https://doi.org/10.1103/PhysRevD.99.108102
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