Performance evaluation of PSD for silicon ECAL

We are developing position sensitive silicon detectors (PSD) which have an electrode at each of four corners so that the incident position of a charged particle can be obtained using signals from the electrodes. It is expected that the position resolution the electromagnetic calorimeter (ECAL) of the ILD detector will be improved by introducing PSD into the detection layers. In this study, we irradiated collimated laser beams to the surface of the PSD, varying the incident position. We found that the incident position can be well reconstructed from the signals if high resistance is implemented in the p+ layer. We also tried to observe the signal of particles by placing a radiative source on the PSD sensor.