Comparison of available measurements of the absolute air-fluorescence yield and determination of its global average value

TL;DR

This paper compares various measurements of the absolute air-fluorescence yield, normalizes them, and applies corrections through detailed simulations to establish a reliable average value with about 5% uncertainty.

Contribution

It provides a comprehensive comparison and correction of existing fluorescence yield measurements, resulting in a more accurate and consistent average value.

Findings

Corrected fluorescence yield measurements show improved consistency.

A reliable average value with 5% uncertainty is established.

Monte Carlo simulations are used for accurate energy deposition calculations.

Abstract

Experimental results of the absolute air-fluorescence yield are given very often in different units (photons/MeV or photons/m) and for different wavelength intervals. In this work we present a comparison of available results normalized to its value in photons/MeV for the 337 nm band at 1013 hPa and 293 K. The conversion of photons/m to photons/MeV requires an accurate determination of the energy deposited by the electrons in the field of view of the experimental set-up. We have calculated the energy deposition for each experiment by means of a detailed Monte Carlo simulation and the results have been compared with those assumed or calculated by the authors. As a result, corrections to the reported fluorescence yields are proposed. These corrections improve the compatibility between measurements in such a way that a reliable average value with uncertainty at the level of 5% is obtained.