Development of the pulse-shape discrimination LSI for Astro-E hard X-ray detector

We have developed the pulse-shape discrimination LSI for Astro-E Hard X-ray Detector (HXD). In the detector, the X-ray and non X-ray backgrounds are reduced efficiently by use of well-type phoswich counters in the compound-eye configuration. The well-type phoswich counter uses GSO(Ce) or YAP(Ce) scintillator for its detection part, and well-shaped BGO for the shielding part. The pulse-shape discriminator (PSD) selects pure GSO (or YAP) hits, rejecting events deposited some energy in BGO. The PSD was designed as a bipolar semi-custom LSI to reduce its power consumption and size, and enhance its reliability. The first delivery of the PSD-LSI chip has been tested, and showed an acceptable performance as the PSD for Astro-E HXD.