Die Entwicklung eines ringabbildenden Cerenkov-Zaehlers fuer den Detektor HERA-B

This dissertation deals with two fundamental questionings of the HERA-B spectrometer's RICH. First an optical system for the imaging of Cerenkov photons was designed, which consisted of a 9 tilted spherical mirror, which was divided in many components, and a focalplane including the photon detectors. It was analyzed by a Monte-Carlo-simulation whether the image faults caused by the aberrations and mechanical inhomogeneities of the mirror hurt the RICH's resolution. The error in ringwidth was #sigma#_p #approx# 4.7 mm. This blurring is much smaller than the granularity of the photon detector which is at least 8 mm. In order to answer the question whether a proportional wire chamber is suited for a photon detector under HERA-B boundary conditions, that means 300 mC of accumulated charge per wire and year, an aging test with CF_4-isobutane (counter gas, relation 80:20) and TMAE (photosensitive substance, concentration 40%) was realized, where the photon flux is created by a UV lamp. After accumulation of 30 - 80 mC per wire some cells lost up to 80% of their gas gain. This means these wire chambers are not suited as photon detectors for HERA-B. With a recently developed typ of photomultiplier (MA-PMT) it was possible to realize an operating alternative. (orig.)Available from TIB Hannover: RN 9448(1997,05) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman