Detection of Cosmic Radiation in the Atmosphere and Radiation Induced in Thunderclouds

0582324 - ÚJF 2024 CZ eng D - Dizertace
Sommer, Marek
Detection of Cosmic Radiation in the Atmosphere and Radiation Induced in Thunderclouds.
Ústav jaderné fyziky AV ČR, v. v. i. Obhájeno: Fakulta jaderná a fyzikálně inženýrská ČVUT v Praze. 31.03.2023. - Praha: České vysoké učení technické v Praze, 2023. 127 s.
Institucionální podpora: RVO:61389005
Klíčová slova: Cosmic rays * ionizing radiation detectors * Terrestrial Gamma Ray Flashes * scintillators * pulse shape discrimination
Obor OECD: Nuclear physics
http://hdl.handle.net/10467/108019

Measurement of cosmic rays onboard aircraft has been used to evaluate the aircrews radiation doses, to create models of radiation field in the atmosphere, to explore influences of space weather to radiation field in the atmosphere and to test
new detectors. Due to the complexity of radiation field encountered onboard aircraft the comprehensive measurement is challenging. Moreover, often the size, weight and power consumption restrictions are imposed on radiation detectors onboard aircraft which makes the task even more challenging. This thesis introduces a concept of small, light-weight detector based on plastic scintillator which can be used in combination with silicon diode detectors to precisely measure dose equivalent without the need for correction factors based on the location. The characterization and calibration of the detector is described and dosimetric method is demonstrated on two flights.
It has been debated if passengers onboard aircraft and aircrews can be irradiated, apart from cosmic rays, by recently discovered rare phenomenon of Terrestrial Gamma Ray Flashes. Although it is very unlikely according to Monte Carlo simulations such events, can cause doses up to 1 Sv. Hence, the research of Terrestrial Gamma Ray Flashes is needed to quantify the likelihood of such severe events and to explore radiation field characteristics. This thesis introduces a detector based on liquid scintillators which focuses on detection of neutrons created by photonuclear reactions during Terrestrial Gamma Ray Flash. The detector was placed at a high–mountain observatory at Lomnický štít and there are plans to place it on a coast in Japan where several Terrestrial Gamma Ray Flashes have been observed.
Trvalý link: https://hdl.handle.net/11104/0350438