Spectrometry of High-Energy Photons on High Mountain Observatory Lomnický Štít During Thunderstorms

Abstract

Lomnický štít, Slovakia, 2634 m above sea level, is known to be a place of extreme electric fields measured during thunderstorms and is thus a suitable place for thunderstorm-related ionising radiation research. We present one of the strongest Thunderstorm ground enhancements (TGE) ever detected, which occurred on 12 September 2021. The TGE was detected with the SEVAN detector and also with the new Georadis RT-56 large volume gamma spectrometer. In the paper, we present spectra of the TGE measured with the spectrometer as well as SEVAN coincidence data supplemented by the data from electric field mill.

How can we simulate ionizing radiation at aviation altitudes from TGFs?

“…The simulation was performed with the general-purpose 3D MC Particle and Heavy Ion Transport code System (PHITS), version 3.24 from 2021 [41], with the built in source terms for GCR and transportation through the atmosphere. [1,27]. The dip in the measured spectrum around channel 14, which can be seen in both the TGE and background spectra, is believed to be caused by the detector geometry since the energy deposition of muons is very dependent on geometry of the detector crystal.…”

“…TGFs might have an important effect on aircraft electronics as theoretically studied in [26]. Authors have previously pointed out the necessity of dedicated measurement campaigns addressing the radiative and particle environment of aircraft near or within thunderstorms [8,27,28,29]. To better understand these phenomena, the Nuclear Physics Institute (NPI) of the Czech Academy of Science CAS (NPI), the Institute of Atmospheric Physics of the CAS (IAP), and the Faculty of Electrical Engineering of the Czech Technical University in Prague (CTU) have created the Research Center of Cosmic Rays and Radiation Events in the Atmosphere (CRREAT).…”

“…Error bars show 1σ errors. Upper-right: MC simulation of muons in RT-56[1,27]. The dip in the measured spectrum around channel 14, which can be seen in both the TGE and background spectra, is believed to be caused by the detector geometry since the energy deposition of muons is very dependent on geometry of the detector crystal.…”