Precise Measurement of the Absolute Yield of Fluorescence Photons in Atmospheric Gases

TL;DR

This paper reports a precise measurement of the absolute fluorescence photon yield in atmospheric gases, which is crucial for improving energy estimates in ultra-high energy cosmic ray observations.

Contribution

It introduces a new calibration method using Cherenkov radiation and cross-checks with laser light to achieve a 5% systematic uncertainty in fluorescence yield measurement.

Findings

Achieved 5% systematic uncertainty in fluorescence photon yield measurement.

Improved the energy scale accuracy for ultra-high energy cosmic ray detection.

Validated calibration methods with Cherenkov radiation and laser sources.

Abstract

We have performed a measurement of the absolute yield of fluorescence photons at the Fermilab Test Beam. A systematic uncertainty at 5% level was achieved by the use of Cherenkov radiation as a reference calibration light source. A cross-check was performed by an independent calibration using a laser light source. A significant improvement on the energy scale uncertainty of Ultra-High Energy Cosmic Rays is expected.