Abstract
To identify the role of the gamma radiation from radon progenies in long-lasting thunderstorm ground enhancement (TGE) flux, the differential energy spectrum is measured with various spectrometers, including precise spectrometer of ORTEC firm built with inches sodium iodide NaI(Tl) crystal; full width at half maximum (FWHM) at 0.6 MeV. The measurements demonstrate that radon progeny radiation significantly contributes to the count rate enhancements measured in the winter of 2018–2019 in the energy range below 3 MeV. However, performed Monte Carlo simulations and observation of long-lasting TGEs with plastic scintillators of various thicknesses and energy thresholds show that TGEs originate in the intracloud electric fields. Radon progenies (mostly spectral lines) contribute to count rate in the low-energy domain.
5 More- Received 4 February 2019
DOI:https://doi.org/10.1103/PhysRevD.99.102002
© 2019 American Physical Society