Publikationsserver der RWTH Aachen University
Search for cosmic-ray antiparticles with bolloon-borne and space-borne experiments
Abstract
dc:descriptionThis thesis discusses two different approaches for the measurement of cosmic-ray antiparticles in the GeV to TeV energy range. The first part studies 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 40km. The detector consists of a transition radiation detector, a time of flight system, a combined silicon and scintillating fiber tracker and an electromagnetic calorimeter. All detectors are placed in a superconducting magnet which creates a field of 0.8T. Several flights are discussed starting from 2012 to get a total of 100 days measurement time with an acceptance of 0.4m^2sr. This work calculates the systematic effects due to interactions of cosmic rays in the atmosphere. GEANT4 simulations were carried out which determine the atmospheric background and attenuation especially for antiparticles. Projected results taking the effects of the atmosphere and the detector properties into account are discussed. The second part covers the AMS-02 experiment which will be installed in 2010 on the International Space Station at an altitude of about 400km for about three years to measure cosmic rays without the influence of Earth's atmosphere. The detector consists of several subdetectors for the determination of particle properties, namely a transition radiation detector, a time of flight system, a cylindrical silicon tracker with eight layers surrounded by an anticoincidence counter in a superconducting magnet with a field of about 0.8T strength, a ring image Cherenkov detector and an electromagnetic calorimeter. The total acceptance with and without the electromagnetic calorimeter is 0.095m^2sr and 0.45m^2sr, respectively. 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 events with external particles crossing the tracker from the side or with particles resulting from interactions within the detector which have possibly disturbed charge and momentum measurements. The last point is especially important for the measurement of antinuclei and antiparticles. The ACC has a modular design of 16 singular plastic scintillator panels which form a cylinder around the tracker with a a diameter of 1100mm, a height of 830,mm and a thickness of 8,mm. The scintillator light is guided by wavelength shifting and clear fibers to photomultiplier tubes. The detector has to cope with several challenges: Fast response and stable operation in a high magnetic field are required. The detector has to withstand a launch with a Space Shuttle into space. The power consumption is only 800mW and the total weight is 54kg. The qualification and performance tests of the panels, fibers, photomultiplier tubes and flight electronics are described. The ACC detection efficiency for charged particles is extracted from testbeam and atmospheric muon measurements and simulations and enters as input to the antimatter measurement performance. In addition, the AMS-02 possibilities for the detection of positrons and antiprotons are studied.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2009
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- von Doetinchem, Philip
- Contributors dc:contributor
-
- Schael, Stefan
Subjects
dc:subject × 40- info:eu-repo/classification/ddc/530
- ISS <Raumfahrt>
- Luftschauer
- Atmosphäre
- Kosmische Strahlung
- Dunkle Materie
- Antimaterie
- Baryonenasymmetrie
- AMS <Teilchendetektor>
- Szintillator
- Lichtwellenleiter
- Sekundärelektronenvervielfacher
- Elementarteilchenphysik
- Monte-Carlo-Simulation
- Physik
- Ballonexperiment
- Astroteilchenphysik
- PEBS
- Detektorbau
- Antikoinzidenzzähler
- atmosphärische Myonen
- Elektroniktest
- Weltraumqualifikation
- Datenanalyse
- Detektor
- astroparticle physics
- balloon
- ISS
- AMS-02
- atmosphere
- air showers
- Monte Carlo simulation
- positron fraction
- antiproton fraction
- anticoincidence counter
- light guides
- photomultiplier
- plastic optical fibers
- atmospheric muons
- inefficiency
Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- eng