• Constraints to do realistic modeling of the electric field ahead of the tip of a lightning leader 

      Skeltved, Alexander Broberg; Østgaard, Nikolai; Mezentsev, Andrey; Lehtinen, Nikolai; Carlson, Brant Edward (Peer reviewed; Journal article, 2017-08)
      Several computer models exist to explain the observation of terrestrial gamma‐ray flashes (TGFs). Some of these models estimate the electric field ahead of lightning leaders and its effects on electron acceleration and ...
    • 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 (Peer reviewed; Journal article, 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 ...
    • Modeling the relativistic runaway electron avalanche and the feedback mechanism with GEANT4 

      Skeltved, Alexander Broberg; Østgaard, Nikolai; Gjesteland, Thomas; Celestin, Sebastien; Carlson, Brant Edward (Peer reviewed; Journal article, 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 ...
    • The modular X- and gamma-ray sensor (MXGS) of the ASIM Payload on the International Space Station 

      Østgaard, Nikolai; Balling, Jan E.; Bjørnsen, Thomas Riis; Brauer, Peter; Budtz-Jørgensen, Carl; Bujwan, Waldemar; Carlson, Brant Edward; Christiansen, Freddy; Connell, Paul; Eyles, Chris; Fehlker, Dominik; Genov, Georgi; Grudzinski, Pawel; Kochkin, Pavlo; Kohfeldt, Anja; Kuvvetli, Irfan; Thomsen, Per Lundahl; Pedersen, Søren Møller; Navarro-Gonzalez, Javier; Neubert, Torsten; Njøten, Kåre; Orleanski, Piotr; Qureshi, Bilal Hasan; Cenkeramaddi, Linga Reddy; Reglero, Victor; Reina, Manuel; Rodrigo, Juan Manuel; Rostad, Maja Elise; Sabau, Maria D.; Kristensen, Steen Savstrup; Skogseide, Yngve; Solberg, Arne Olav; Stadsnes, Johan; Ullaland, Kjetil; Yang, Shiming (Peer reviewed; Journal article, 2019-02-18)
      The Modular X- and Gamma-ray Sensor (MXGS) is an imaging and spectral X- and Gamma-ray instrument mounted on the starboard side of the Columbus module on the International Space Station. Together with the Modular Multi-Spectral ...
    • Time domain simulations of preliminary breakdown pulses in natural lightning 

      Carlson, Brant Edward; Liang, Can; Bitzer, Phillip M.; Christian, Hugh J. (Peer reviewed; Journal article, 2015-06)
      Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to ...