Articles | Volume 6, issue 2
Research article
13 Jul 2017
Research article |  | 13 Jul 2017

TARANIS XGRE and IDEE detection capability of terrestrial gamma-ray flashes and associated electron beams

David Sarria, Francois Lebrun, Pierre-Louis Blelly, Remi Chipaux, Philippe Laurent, Jean-Andre Sauvaud, Lubomir Prech, Pierre Devoto, Damien Pailot, Jean-Pierre Baronick, and Miles Lindsey-Clark

Abstract. With a launch expected in 2018, the TARANIS microsatellite is dedicated to the study of transient phenomena observed in association with thunderstorms. On board the spacecraft, XGRE and IDEE are two instruments dedicated to studying terrestrial gamma-ray flashes (TGFs) and associated terrestrial electron beams (TEBs). XGRE can detect electrons (energy range: 1 to 10 MeV) and X- and gamma-rays (energy range: 20 keV to 10 MeV) with a very high counting capability (about 10 million counts per second) and the ability to discriminate one type of particle from another. The IDEE instrument is focused on electrons in the 80 keV to 4 MeV energy range, with the ability to estimate their pitch angles.

Monte Carlo simulations of the TARANIS instruments, using a preliminary model of the spacecraft, allow sensitive area estimates for both instruments. This leads to an averaged effective area of 425 cm2 for XGRE, used to detect X- and gamma-rays from TGFs, and the combination of XGRE and IDEE gives an average effective area of 255 cm2 which can be used to detect electrons/positrons from TEBs. We then compare these performances to RHESSI, AGILE and Fermi GBM, using data extracted from literature for the TGF case and with the help of Monte Carlo simulations of their mass models for the TEB case.

Combining this data with the help of the MC-PEPTITA Monte Carlo simulations of TGF propagation in the atmosphere, we build a self-consistent model of the TGF and TEB detection rates of RHESSI, AGILE and Fermi. It can then be used to estimate that TARANIS should detect about 200 TGFs yr−1 and 25 TEBs yr−1.

Short summary
The TARANIS spacecraft will be launched at the end of 2018. It is one of the first dedicated to the study of terrestrial gamma-ray flashes (TGF) and associated electrons (TEB), produced by thunderstorms. We present two of the six instruments on board the TARANIS spacecraft: a gamma-ray and energetic electron detector (XGRE) and an electron detector (IDEE). We compare them to other instruments that have already detected TGF and TEB, and use them to estimate the detection rate of TARANIS.