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arXiv · 1601.00551

Molecular Bremsstrahlung Radiation at GHz Frequencies in Air

I. Al Samarai·C. Berat·O. Deligny·A. Letessier-Selvon·F. Montanet·M. Settimo·P. Stassi
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Abstract

A detection technique for ultra-high energy cosmic rays, complementary to the fluorescence technique, would be the use of the molecular Bremsstrahlung radiation emitted by low-energy ionization electrons left after the passage of the showers in the atmosphere. In this article, a detailed estimate of the spectral intensity of photons at ground level originating from this radiation is presented. The spectral intensity expected from the passage of the high-energy electrons of the cascade is also estimated. The absorption of the photons in the plasma of electrons/neutral molecules is shown to be negligible. The obtained spectral intensity is shown to be $2\times10^{-21} $W cm$^{-2}$ GHz$^{-1}$ at 10 km from the shower core for a vertical shower induced by a proton of $10^{17.5}$ eV. In addition, a recent measurement of Bremsstrahlung radiation in air at gigahertz frequencies from a beam of electrons produced at 95 keV by an electron gun is also discussed and reasonably reproduced by the model.

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I. Al Samarai, C. Berat, O. Deligny, A. Letessier-Selvon, F. Montanet, M. Settimo, P. Stassi. 2016-02-09. Molecular Bremsstrahlung Radiation at GHz Frequencies in Air. https://doi.org/10.1103/physrevd.93.052004

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