Secondary electron spectrum from 30 GeV to 10 TeV in the upper atmosphere

Yoshiko Komori, Tadashi Kobayashi, Kenji Yoshida, Jun Nishimura

Research output: Contribution to conferencePaperpeer-review


In the previous paper [1], we have evaluated the secondary electron spectrum in the upper atmosphere using our direct measurements of atmospheric gamma-ray spectrum in the 30 GeV- 10 TeV energy range. We have solved the simultaneous equations of electron and gamma-ray spectrum using the cascade shower theory combined by the gamma-ray production rate in the atmosphere. In this paper we present more precise solutions taking into account some nuclear decay modes, particularly, Dalitz decay mode which produces pair electrons directly from neutral pions, contributing about 10% to the secondary spectrum. The analytic results solved exactly are compared with those of the Monte Carlo simulation(MC), and the secondary electron/gammaray ratio shows the good agreement with each other. The contribution of Dalitz electrons increases the importance at the higher altitude, and cannot be negligible in the TeV electron balloon measurements. Our observed atmospheric gamma-ray spectrum is 20% higher than the results of MC as indicated previously [2], so that the estimates of secondary electrons become higher than 20% than those of MC. Although the discrepancy still remains, for the correction of primary electron spectrum we use the secondary spectrum obtained from the measured gamma-ray spectrum, because it does not include uncertainties of nuclear interaction models of MC.

Original languageEnglish
Publication statusPublished - 2009 Jan 1
Event31st International Cosmic Ray Conference, ICRC 2009 - Lodz, Poland
Duration: 2009 Jul 72009 Jul 15


Conference31st International Cosmic Ray Conference, ICRC 2009


  • Atmosphere
  • Nuclear interaction
  • Secondary electrons

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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