Simulations of the SVOM/ECLAIRs dynamic background: a fast, accurate and general approach for wide-field hard X-ray instruments

  • Sujay MateEmail author
  • Laurent Bouchet
  • Jean-Luc Atteia
  • Arnaud Claret
  • Bertrand Cordier
  • Nicolas Dagoneau
  • Olivier Godet
  • Aleksandra Gros
  • Stéphane Schanne
  • Henri Triou
Original Article


The Space Variable Object Monitor (SVOM) is a forthcoming Chinese - French astrophysics space mission dedicated to the study of Gamma-ray bursts and high-energy transients. ECLAIRs, a wide-field hard X-ray coded mask imager, is the leading instrument for the transient detection and their first localisation. The sensitivity of such instruments is usually limited by the background, either of instrumental or astrophysical origin. Detailed estimations of the background are obtained by simulating the interaction of particles with the matter using, in the present case, the GEANT4 Monte-Carlo toolkit. However, this is a time consuming process, especially when it is needed to carry out all possible geometrical and orbital configurations. Instead, we present a much faster method that allows computing the background in either a static or dynamic (time dependent) way. The method is based on the preliminary calculation of a large particle database using the GEANT4 toolkit followed by a selection process based on the incoming direction and energy of the particles. This approach is as accurate as direct Monte-Carlo methods, while it reduces the computation time by a factor of 103 − 104 for our application. We apply this method to compute the SVOM/ECLAIRs dynamic background.


Instrumentation: detectors Methods: numerical (Monte - Carlo) Techniques: miscellaneous Telescopes (SVOM/ECLAIRs) 



We thank the anonymous referee for the detailed and valuable suggestions which have helped us to improve the paper.


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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  • Sujay Mate
    • 1
    Email author
  • Laurent Bouchet
    • 1
  • Jean-Luc Atteia
    • 1
  • Arnaud Claret
    • 2
  • Bertrand Cordier
    • 2
  • Nicolas Dagoneau
    • 2
  • Olivier Godet
    • 1
  • Aleksandra Gros
    • 2
  • Stéphane Schanne
    • 2
  • Henri Triou
    • 2
  1. 1.IRAP, Université de Toulouse, CNES, CNRS, UPSToulouseFrance
  2. 2.CEA Paris Saclay, IRFU/Département d’Astrophysique - AIMGif sur YvetteFrance

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