• Constraining Spectral Models of a Terrestrial GammaRay Flash From a Terrestrial Electron Beam Observation by the Atmosphere-Space Interactions Monitor 

      Sarria, David Alexandre Stephan; Østgaard, Nikolai; Kochkin, Pavlo; Lehtinen, Nikolai Grigorievich; Mezentsev, Andrey; Marisaldi, Martino; Lindanger, Anders; Maiorana, Carolina; Carlson, Brant Edward; Neubert, Torsten; Reglero, Victor; Ullaland, Kjetil; Yang, Shiming; Genov, Georgi; Qureshi, Bilal Hasan; Budtz-Jørgensen, Carl; Kuvvetli, Irfan; Christiansen, Freddy; Chanrion, Olivier; Navarro-Gonzalez, Javier; Connel, P.; Eyles, Chris (Journal article; Peer reviewed, 2021)
      Terrestrial Gamma ray Flashes (TGFs) are short flashes of high energy photons, produced by thunderstorms. When interacting with the atmosphere, they produce relativistic electrons and positrons, and a part gets bounded to ...
    • 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 ...
    • Spectral Analysis of Individual Terrestrial Gamma-ray Flashes Detected by ASIM 

      Lindanger, Anders; Marisaldi, Martino; Sarria, David Alexandre Stephan; Østgaard, Nikolai; Lehtinen, Nikolai Grigorievich; Skeie, Chris Alexander Kallevik; Mezentsev, Andrey; Kochkin, Pavlo; Ullaland, Kjetil; Yang, Shiming; Genov, Georgi; Carlson, Brant Edward; Köhn, Christoph; Navarro-Gonzalez, Javier; Connell, Paul H.; Reglero, Victor; Neubert, Torsten (Journal article; Peer reviewed, 2021)
      The Atmosphere-Space Interactions Monitor (ASIM) is the first instrument in space specifically designed to observe terrestrial gamma-ray flashes (TGFs). TGFs are high energy photons associated with lightning flashes and ...
    • 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 ...