2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/222359This thesis deals with detector concepts aiming at a precise measurement of the cosmic-ray positron fraction extending to an as yet unreached range of energy. The indirect search for dark matter is the main motivation for this endeavour.177 pages, PhD thesis submitted to RWTH Aachen University, a version with high-resolution figures is available at http://accms04.physik.rwth-aachen.de/~hgast/documents/diss.pdfAstrophysics of GalaxiesInstrumentation and Methods for Astrophysicstext