Search for Cosmic-Ray Antiparticles with Balloon-borne and Space-borne Experiments

TL;DR

This thesis explores two methods for measuring cosmic-ray antiparticles using balloon-borne and space-borne experiments, focusing on detector design, background simulation, and background rejection techniques to improve antiparticle detection accuracy.

Contribution

It presents a detailed simulation and analysis of antiparticle detection prospects with the PEBS balloon experiment and the AMS-02 space experiment, including background mitigation strategies.

Findings

GEANT4 simulations of atmospheric background for PEBS

Design considerations for AMS-02 anticoincidence counter system

Enhanced background rejection for antiparticle measurements

Abstract

This thesis discusses two different approaches for the measurement of cosmic-ray antiparticles in the GeV to TeV energy range. The first part of this thesis discusses the prospects of antiparticle flux measurements with the proposed PEBS detector. The project allots long duration balloon flights at one of Earth's poles at an altitude of 40 km. GEANT4 simulations were carried out which determine the atmospheric background and attenuation especially for antiparticles. The second part covers the AMS-02 experiment which will be installed in 2010 on the International Space Station at an altitude of about 400 km for about three years to measure cosmic rays without the influence of Earth's atmosphere. The present work focuses on the anticoincidence counter system (ACC). The ACC is needed to reduce the trigger rate during periods of high fluxes and to reject external particles crossing the tracker from the side or particles resulting from interactions within the detector which would otherwise disturb the clean charge and momentum measurements. The last point is especially important for the measurement of antinuclei and antiparticles.