In this project, the homogeneity of the detection efficiency of two silicon detectors were examined using a radioactive alpha-source, 241Am, to study the surfaces of the detectors by exposing a small part of the detector at a time. By then observing the variations of the deposited alpha-energies at different positions on the detector, one can map the differences in the homogeneity of the surface. Many variations of different magnitudes were found; some variations can reasonably be represented by either variations in the dead layer or residue glue along the edges. Some variations seemed best explained by pieces of dust or dirt on the surface. The possibility of using heavy fission fragments from the decay of 252Cf to compare the effects was explored but shown to be non-feasible in the scope of this project. Finally, proposals for further work and improvements are discussed.

The goal of the project was to simulate a typical silicon detectorresponse in an experiment made at the Tandem lab in Uppsala. The plasma delay time was analyzed by simulating the experiment. Three different models of the plasma delay time were introduced and their effects on time of flight measurements were studied. A continuation of the main goal was to see if the inserted PDT models could be extracted from the simulations when being treated as a pseudo experiment, to see theoverall effectiveness of the experiment. When comparing the final simulations with actual measurements, it was concluded that the main properties of the detector response had been featured and that the simulations were successful. The successful extraction of the inserted plasma delay times and their dependencies on energy also proved that the experiment was a good one. The result of the project was that one of the models seemed to have a strong mass dependence, however with no clear dependence on the energy. The other two models showed a somewhat similar dependence on energy. One of the two models also showed a relatively weak mass dependence.