Determination of the homogeneity of the detection efficiency of silicon detectors using light ions

Abstract: 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.