Cerenkov angle and charge reconstruction with the RICH detector of the AMS experiment

TL;DR

This paper discusses methods for reconstructing Cerenkov angle and electric charge using the AMS RICH detector, achieving high-precision velocity measurements and addressing background photon challenges.

Contribution

It introduces two reconstruction methods for Cerenkov angle and charge, including a Likelihood approach for velocity and an efficiency-based method for charge.

Findings

Velocity resolution of about 0.1% for protons

Effective charge reconstruction considering background photon variability

Demonstration of reconstruction methods for space-based particle detection

Abstract

The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cerenkov (RICH) detector, for measurements of particle electric charge and velocity. In this note, two possible methods for reconstructing the Cerenkov angle and the electric charge with the RICH, are discussed. A Likelihood method for the Cerenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution of around 0.1%. The existence of a large fraction of background photons which can vary from event to event, implied a charge reconstruction method based on an overall efficiency estimation on an event-by-event basis.