Now showing items 1-7 of 7

    • Meter-scale spark X-ray spectrum statistics 

      Carlson, Brant Edward; Østgaard, Nikolai; Kochkin, Pavlo; Grøndahl, Øystein; Nisi, Ragnhild Schrøder; Weber, Kristian; Scherrer, Zack; LeCaptain, Kristian (AGU Publications, 2015-11-13)
      X-ray emission by sparks implies bremsstrahlung from a population of energetic electrons, but the details of this process remain a mystery. We present detailed statistical analysis of X-ray spectra detected by multiple ...
      Journal article
    • Modeling the relativistic runaway electron avalanche and the feedback mechanism with GEANT4 

      Skeltved, Alexander Broberg; Østgaard, Nikolai; Gjesteland, Thomas; Celestin, Sebastien; Carlson, Brant Edward (Wiley, 2014-11)
      This paper presents the first study that uses the GEometry ANd Tracking 4 (GEANT4) toolkit to do quantitative comparisons with other modeling results related to the production of terrestrial gamma ray flashes and high-energy ...
      Journal article
    • A new population of terrestrial gamma-ray flashes in the RHESSI data 

      Østgaard, Nikolai; Albrechtsen, Kjetil; Gjesteland, Thomas; Collier, Andrew B. (AGU Publications, 2015-12-23)
      Terrestrial gamma-ray flashes (TGFs) are the most energetic photon phenomenon occurring naturally on Earth. An outstanding question is as follows: Are these flashes just a rare exotic phenomenon or are they an intrinsic ...
      Journal article
    • Observation of intrinsically bright terrestrial gamma ray flashes from the Mediterranean basin 

      Gjesteland, Thomas; Østgaard, Nikolai; Laviola, Sante; Miglietta, M M; Arnone, Enrico; Marisaldi, Martino; Fuschino, F; Collier, Andrew B.; Fabro, F; Montanya, J (AGU Publications, 2015-12-14)
      We present three terrestrial gamma ray flashes (TGFs) observed over the Mediterranean basin by the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) satellite. Since the occurrence of these events in the ...
      Journal article
    • Search for Terrestrial Electron Beams in SAMPEX HILT data 

      Aamodt, Vegard (The University of Bergen, 2015-06-01)
      The Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) was a low polar orbiting satellite operating from 1992 to 2012. The goal of this master project has been to see if Terrestrial Electron Beams (TEBs), ~20 ...
      Master thesis
    • Search for Terrestrial Gamma-ray Flashes in AGILE data by correlation with ground-based lightning measurements 

      Lindanger, Anders (The University of Bergen, 2018-06-16)
      Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond bursts of high energy photons, associated with lightning flashes produced inside thunderstorms. The Astro-Rivelatore Gamma a Immagini Leggero (AGILE) satellite is ...
      Master thesis
    • Search for unidentified Terrestrial Gamma-ray Flashes 

      Albrechtsen, Kjetil Haakonseth (The University of Bergen, 2015-06-01)
      Terrestrial Gamma-ray Flashes (TGFs) are the most energetic natural phenomena on Earth with possible energies above 40MeV. They consist of large amounts of energetic photons ( 10^17 to 10^19 ) produced in thunderstorms at ...
      Master thesis