Further developments on an ISPA-camera for gamma-rays in nuclear medicine

The ISPA (Imaging Silicon Pixel Array)-tube is a position-sensitive hybrid photon detector. Originally developed for high energy physics purposes, it has also been used for biomedical applications. Two kinds of ISPA-tube prot otypes have been tested successfully in the field of gamma ray imaging. The current developments aim at obtaining a detector dedicated to single photo n emission imaging. In this paper, we shall present the very first use in a gamma-camera of a new ISPA-tube prototype having an increased active input surface of 40mm diameter and a de-magnifying electron optics. The expected advantages of an ISPA-tube equipped with an input window made out of YAP-c rystal will also be pointed out by presenting results obtained with a Hybri d PhotoMultiplier Tube equipped with such a YAP window.