Systematic studies on the radiation resistance of silicon detectors for the application in high-energy physics experiments

In this thesis the radiation hardness of silicon detectors in high energy physics experiments was investigated systematically. These data show that the bulk damage corresponds independently of the particle type to the damage functions of the non ionizing energy loss, if the energy of the energy of the primary knock-on atom is above a threshold value. Accordingly the damage functions were used for the normalization of different radiation fields to 1 MeV neutrons. With respect to the detector performance detailed measurements of the change in the effective donor concentration, the leakage current increase and charge collection deficiency were investigated as function of the particle fluence and the time after irradiation. Special emphasis was put on the self annealing effects at room temperature in order to separate the respective damage generation and its subsequent self annealing. The change in the effective donor concentration is caused by donor and acceptor removal and radiation induced acceptor like centers. For n-type silicon this leads to the conversion to p-type material, which was here, for the first time, proved with short ranged α-particles. Also a modification of defects was observed during the long term self annealing leading to a further creation of acceptor like centers. The radiation induced leakage current depends on the conduction type. Taking the self annealing into account the current increase in long term exposure is governed by a damage rate of 4.10-17 Acm-1. The charge collection efficiency for mip's was calculated from the electron and hole trapping, which was studied separately. (orig./HSI)