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

Education for elders in the U.S.: opportunities and challenges in the context of the demographic change

In the next decades a societal change, caused by a continuous demographic shift, is imminent for the USA. Compared to Germany, where the birth rate is likely to stagnate at a low level, the effect of immigration into the United States is more pronounced. Here not only the proportion of elderly in the total population will increase, but also the total population itself. These developments will bring great social and political challenges that call for appropriate action. Looking at the increasing number of mature adults it is especially important to keep in mind that the remaining time after retirement is not only the rest of the life, but rather an important and distinctive life stage which can last easily 20 to 30 years

Una posible influencia: la Epístola de la Contemplación (Risālat al-iʿtibār) de Ibn Masarra (m. 931) y Ḥayy ibn Yaqẓān (Risālat Ḥayy ibn Yaqẓān) de Ibn Ṭufayl’s (m. 1185)

This article makes the case for considering Ibn Masarra’s Epistle of Contemplation (Risālat al-iʿtibār) another possible influence on Ibn Ṭufayl’s famous philosophical tale, Ḥayy ibn Yaqẓān. The overlap in the basic arguments the two works make regarding the compatibility of reason and revelation as the two paths of attaining knowledge and the works’ similar epistemological uses of the concept of fiṭra as basic to the rational ascent they both discuss suggest that Ibn Masarra’s epistle provided some inspiration for Ibn Ṭufayl’s tale. However, a comparison of the two works also demonstrates important differences in their respective conceptions of the end of contemplation and of fiṭra and, relatedly, their takes on the parity of reason and revelation. Weighing both the significant overlaps and the important differences, this article makes the case for a meaningful connection between the two Andalusian texts. Given the relative scarcity of historical data on the two authors, the article does not make any arguments regarding the material history of either text or the historical circumstances of their authors. Instead, it concludes that in spite of the divergent nuances between the two works, their parallels justify considering Ibn Masarra’s epistle another potential influence on the structure and overall aims of Ibn Ṭufayl’s tale.Este artículo plantea la posibilidad de considerar la Epístola de la Contemplación (Risālat al-iʿtibār) de Ibn Masarra como otra posible influencia en la famosa novela filosófica de Ibn Ṭufayl, Ḥayy ibn Yaqẓān. Las características compartidas en los argumentos básicos de las dos obras sobre la compatibilidad de la razón y la revelación como los dos caminos para alcanzar el conocimiento y su similar uso epistemológico del concepto de fiṭra como la base del ascenso racional demuestran que la epístola de Ibn Masarra constituyó una fuente para la historia ideada por Ibn Ṭufayl. Sin embargo, una comparación de ambas obras demuestra diferencias importantes en sus concepciones del fin de la contemplación y de la fiṭra y, de ahí, en las ideas de cada autor acerca de la paridad entre razón y revelación. Considerando tanto sus características compartidas más significativas como sus diferencias más importantes, este artículo plantea la posible existencia de una conexión significativa entre los dos textos andalusíes. Dado que hay una escasez relativa de datos históricos sobre los dos autores, este artículo no aborda la historia material de ninguno de los textos o las circunstancias históricas de sus autores. En cambio, concluye que, a pesar de los matices divergentes entre las dos obras, sus paralelos justifican considerar la epístola de Ibn Masarra como otra influencia posible en la estructura y objetivos de la novela de Ibn Ṭufayl

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

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$_{min}$) 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 flight of the GAPS prototype experiment

The General AntiParticle Spectrometer experiment (GAPS) is foreseen to carry out a dark matter search using low-energy cosmic ray antideuterons at stratospheric altitudes with a novel detection approach. A prototype flight from Taiki, Japan was carried out in June 2012 to prove the performance of the GAPS instrument subsystems (Lithium-drifted Silicon tracker and time-of-flight) and the thermal cooling concept as well as to measure background levels. The flight was a success and the stable flight operation of the GAPS detector concept was proven. During the flight about 106 charged particle triggers were recorded, extensive X-ray calibrations of the individual tracker modules were performed by using an onboard X-ray tube, and the background level of atmospheric and cosmic X-rays was measured. The behavior of the tracker performance as a function of temperature was investigated. The tracks of charged particle events were reconstructed and used to study the tracking resolution, the detection efficiency of the tracker, and coherent X-ray backgrounds. A timing calibration of the time-of-flight subsystem was performed to measure the particle velocity. The flux as a function of flight altitude and as a function of velocity was extracted taking into account systematic instrumental effects. The developed analysis techniques will form the basis for future flights