Velocity and charge reconstruction with the AMS/RICH detector

TL;DR

This paper discusses the design and methods of the AMS/RICH detector for the ISS, focusing on reconstructing particle velocity and charge with high precision using likelihood and counting techniques.

Contribution

It introduces a likelihood-based Cherenkov angle reconstruction method and a charge estimation approach for the AMS/RICH detector, demonstrating their effectiveness.

Findings

Velocity resolution around 0.1% for protons

Effective charge reconstruction via photoelectron counting

Application of methods yields promising results

Abstract

The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station (ISS) in 2008, will be equipped with a proximity focusing Ring Imaging CHerenkov detector (RICH). This detector will be equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light-guides, enabling measurements of particle electric charge and velocity. A likelihood method for the Cherenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution around 0.1%. The electric charge reconstruction is based on the counting of the number of photoelectrons and on an overall efficiency estimation on an event-by-event basis. Results from the application of both methods are presented.