8 research outputs found
Search for Cosmic-Ray Antiparticles with Balloon-borne and Space-borne Experiments
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, errat
A new simulation-based model for calculating post-mortem intervals using developmental data for Lucilia sericata (Dipt.: Calliphoridae)
Homicide investigations often depend on the determination of a minimum
post-mortem interval (PMI) by forensic entomologists. The age of the
most developed insect larvae (mostly blow fly larvae) gives reasonably reliable
information about the minimum time a person has been dead. Methods such as
isomegalen diagrams or ADH calculations can have problems in their reliability,
so we established in this study a new growth model to calculate the larval age
of \textit{Lucilia sericata} (Meigen 1826). This is based on the actual
non-linear development of the blow fly and is designed to include
uncertainties, e.g. for temperature values from the crime scene. We used
published data for the development of \textit{L. sericata} to estimate
non-linear functions describing the temperature dependent behavior of each
developmental state. For the new model it is most important to determine the
progress within one developmental state as correctly as possible since this
affects the accuracy of the PMI estimation by up to 75%. We found that PMI
calculations based on one mean temperature value differ by up to 65% from PMIs
based on an 12-hourly time temperature profile. Differences of 2\degree C in
the estimation of the crime scene temperature result in a deviation in PMI
calculation of 15 - 30%.Comment: 14 pages, 5 figures, 1 tabl
The AMS-02 Anticoincidence Counter
The AMS-02 detector will measure cosmic rays on the International Space
Station. This contribution will cover production, testing, space qualification
and integration of the AMS-02 anticoincidence counter. The anticoincidence
counter is needed to to assure a clean track reconstruction for the charge
determination and to reduce the trigger rate during periods of high flux.Comment: IPRD08 conference proceeding. Will be published in Nuclear Physics B
(Proceedings Supplement