Properties of the most recent Hamamatsu avalanche photodiode

In a development program Hamamatsu Photonics improved their avalanche photo-diodes significantly. The first milestones, reduction of the so-called nuclear counter effect, the effective thickness contributing to signals from charged particles, without increasing the capacitance, the dark current and the excess noise factor has been achieved. In parallel the radiation hardness against neutron and gamma irradiation has been improved. Results on the most recent prototype will be presented.