Spatial resolution of the Medipix2 X-ray imaging detector system

The charge sharing present in a 55 micrometer square pixel matrix of 300 micrometer thick silicon is examined. This is achieved using a commercial simulation package to investigate the diffusion effects on the charge cloud of created electrons and holes. The total fraction of charge shared is found to be 20.8%, but this can be reduced by the addition of a minimum threshold level of detection. The optimum level giving all of the signal but with the minimum of noise is found to leave 10.4% charge shared on average.