  We have investigated charge sharing among the anode strips of a CdZnTe (CZT)
detector using a 30 micrometer collimated gamma-ray beam. We compared the
laboratory measurements with the predictions from our modeling of the charge
transport within the detector. The results indicate that charge sharing is a
function of the interaction depth and the energy of the incoming photon. Also,
depending on depth, a fraction of the electrons might drift to the inter-anode
region causing incomplete charge collection. Here, we show that photoelectron
range and diffusion of the charge cloud are the principal causes of charge
sharing and obtain limits on the size of the electron cloud as a function of
position in the detector.
