Observational and Theoretical Overview of High-Energy Atmospheric Physics

2021 ◽  
pp. 7-39
Author(s):  
Yuuki Wada
Keyword(s):  
High Energy ◽  
Atmospheric Physics ◽  
Theoretical Overview

scholarly journals High-Energy Atmospheric Physics: Terrestrial Gamma-Ray Flashes and Related Phenomena

2012 ◽  
Vol 173 (1-4) ◽  
pp. 133-196 ◽  
Author(s):  
Joseph R. Dwyer ◽  
David M. Smith ◽  
Steven A. Cummer
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Atmospheric Physics

Supplementary material to "Evaluation of Monte Carlo tools for high energy atmospheric physics"

2016 ◽  
Author(s):  
Casper Rutjes ◽  
David Sarria ◽  
Alexander Broberg Skeltved ◽  
Alejandro Luque ◽  
Gabriel Diniz ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Energy ◽  
Atmospheric Physics ◽  
Supplementary Material

scholarly journals Evaluation of Monte Carlo tools for high energy atmospheric physics

2016 ◽  
Vol 9 (11) ◽  
pp. 3961-3974 ◽  
Author(s):  
Casper Rutjes ◽  
David Sarria ◽  
Alexander Broberg Skeltved ◽  
Alejandro Luque ◽  
Gabriel Diniz ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Gamma Ray ◽  
High Energy ◽  
Atmospheric Physics ◽  
Computational Performance ◽  
Electron Positron ◽  
Custom Made ◽  
Electric And Magnetic Fields ◽  
Energy Cutoff ◽  
High Energy Particles

Abstract. The emerging field of high energy atmospheric physics (HEAP) includes terrestrial gamma-ray flashes, electron–positron beams and gamma-ray glows from thunderstorms. Similar emissions of high energy particles occur in pulsed high voltage discharges. Understanding these phenomena requires appropriate models for the interaction of electrons, positrons and photons of up to 40 MeV energy with atmospheric air. In this paper, we benchmark the performance of the Monte Carlo codes Geant4, EGS5 and FLUKA developed in other fields of physics and of the custom-made codes GRRR and MC-PEPTITA against each other within the parameter regime relevant for high energy atmospheric physics. We focus on basic tests, namely on the evolution of monoenergetic and directed beams of electrons, positrons and photons with kinetic energies between 100 keV and 40 MeV through homogeneous air in the absence of electric and magnetic fields, using a low energy cutoff of 50 keV. We discuss important differences between the results of the different codes and provide plausible explanations. We also test the computational performance of the codes. The Supplement contains all results, providing a first benchmark for present and future custom-made codes that are more flexible in including electrodynamic interactions.

scholarly journals Evaluation of Monte Carlo tools for high-energy atmospheric physics II: relativistic runaway electron avalanches

2018 ◽  
Vol 11 (11) ◽  
pp. 4515-4535 ◽  
Author(s):  
David Sarria ◽  
Casper Rutjes ◽  
Gabriel Diniz ◽  
Alejandro Luque ◽  
Kevin M. A. Ihaddadene ◽  
...  
Keyword(s):  
Electron Energy ◽  
Electric Fields ◽  
Runaway Electron ◽  
High Energy ◽  
Energy Spectra ◽  
Breakdown Field ◽  
Atmospheric Physics ◽  
Electron Avalanches ◽  
Set Up ◽  
Good Agreement

Abstract. The emerging field of high-energy atmospheric physics studies how high-energy particles are produced in thunderstorms, in the form of terrestrial γ-ray flashes and γ-ray glows (also referred to as thunderstorm ground enhancements). Understanding these phenomena requires appropriate models of the interaction of electrons, positrons and photons with air molecules and electric fields. We investigated the results of three codes used in the community – Geant4, GRanada Relativistic Runaway simulator (GRRR) and Runaway Electron Avalanche Model (REAM) – to simulate relativistic runaway electron avalanches (RREAs). This work continues the study of Rutjes et al. (2016), now also including the effects of uniform electric fields, up to the classical breakdown field, which is about 3.0 MV m−1 at standard temperature and pressure. We first present our theoretical description of the RREA process, which is based on and incremented over previous published works. This analysis confirmed that the avalanche is mainly driven by electric fields and the ionisation and scattering processes determining the minimum energy of electrons that can run away, which was found to be above ≈10 keV for any fields up to the classical breakdown field. To investigate this point further, we then evaluated the probability to produce a RREA as a function of the initial electron energy and of the magnitude of the electric field. We found that the stepping methodology in the particle simulation has to be set up very carefully in Geant4. For example, a too-large step size can lead to an avalanche probability reduced by a factor of 10 or to a 40 % overestimation of the average electron energy. When properly set up, both Geant4 models show an overall good agreement (within ≈10 %) with REAM and GRRR. Furthermore, the probability that particles below 10 keV accelerate and participate in the high-energy radiation is found to be negligible for electric fields below the classical breakdown value. The added value of accurately tracking low-energy particles (<10 keV) is minor and mainly visible for fields above 2 MV m−1. In a second simulation set-up, we compared the physical characteristics of the avalanches produced by the four models: avalanche (time and length) scales, convergence time to a self-similar state and energy spectra of photons and electrons. The two Geant4 models and REAM showed good agreement on all parameters we tested. GRRR was also found to be consistent with the other codes, except for the electron energy spectra. That is probably because GRRR does not include straggling for the radiative and ionisation energy losses; hence, implementing these two processes is of primary importance to produce accurate RREA spectra. Including precise modelling of the interactions of particles below 10 keV (e.g. by taking into account molecular binding energy of secondary electrons for impact ionisation) also produced only small differences in the recorded spectra.

Supplementary material to "Evaluation of Monte Carlo tools for high energy atmospheric physics II: relativistic runaway electron avalanches"

2018 ◽  
Author(s):  
David Sarria ◽  
Casper Rutjes ◽  
Gabriel Diniz ◽  
Alejandro Luque ◽  
Kevin M. A. Ihaddadene ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Runaway Electron ◽  
High Energy ◽  
Atmospheric Physics ◽  
Supplementary Material ◽  
Electron Avalanches
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