Measurement of the near-infrared fluorescence of the air for the detection of ultra-high-energy cosmic rays

TL;DR

This study explores the near-infrared fluorescence of air caused by electron excitation, assessing its potential for detecting ultra-high-energy cosmic rays through spectral measurements and yield comparisons.

Contribution

It provides the first detailed measurement of near-infrared air fluorescence and evaluates its feasibility for cosmic ray detection.

Findings

Near-infrared fluorescence spectra of nitrogen and oxygen were recorded.

The light yield in the near-infrared was quantified and compared to ultraviolet fluorescence.

Potential advantages and challenges of using near-infrared fluorescence for cosmic ray detection were discussed.

Abstract

We have investigated the fluorescence emission in the Near Infrared from the air and its main components, nitrogen and oxygen. The gas was excited by a 95kV electron beam and the fluorescence light detected by an InGaAs photodiode, sensitive down to about 1700nm. We have recorded the emission spectra by means of a Fourier Transform Infrared spectrometer. The light yield was also measured by comparing the Near Infrared signal with the known Ultraviolet fluorescence, detected by a Si photodiode. The possibility of using the Near Infrared fluorescence of the atmosphere to detect Ultra-High-Energy Cosmic Rays is discussed, showing the pros and the cons of this novel method.