The RICH detector of the AMS-02 experiment: status and physics prospects
ABSTRACT The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV. It is equipped with several subsystems, one of which is a proximity focusing RICH detector with a dual radiator (aerogel+NaF) that provides reliable measurements for particle velocity and charge. The assembly and testing of the AMS RICH is currently being finished and the full AMS detector is expected to be ready by the end of 2008. The RICH detector of AMS-02 is presented. Physics prospects are briefly discussed.
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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. Comment: 153 pages, 250 figures, accepted PhD thesis, RWTH Aachen University 2009, errata
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ABSTRACT: The AMS-2 experiment will be launched with the Space Shuttle Discovery and installed on the International Space Station in 2010. It is designed to perform precision spectroscopy of many different cosmic-ray species including electrons and positrons. While the nature of dark matter is as yet unknown, dark matter annihilating in the Galactic halo is a well-motivated source of cosmic-ray electrons and positrons. The cosmic-ray positron fraction data available so far show significant deviations between different measurements and from the expectation for purely secondary production. The differences between the measurements up to particle energies of 6 GeV can be understood in a framework of charge-sign-dependent solar modulation and the spectra show excellent agreement if corrected for these time-dependent effects. Recent observations of an excess in the high-energy electron spectrum by ATIC might be connected to the excess in the positron fraction. A possible source of both signatures could be dark matter annihilation or a nearby pulsar. A measurement of the anisotropy of high-energy electrons could distinguish between both scenarios. Therefore the sky coverage of AMS-2 will be discussed in addition to possible dark matter scenarios and the sensitivity of the AMS-2 experiment to these effects.New Journal of Physics 10/2009; 11(10):105021. DOI:10.1088/1367-2630/11/10/105021 · 3.67 Impact Factor