Development and qualification of the HXD-II onboard Astro-E2

Abstract

The Hard X-ray Detector (HXD-II), one of instruments onboard the <i>Astro-E</i>2 satellite to be launched in February 2005, is in the final stage of its development. The HXD-II probes the universe in the energy range of 10-600 keV with a sensitivity by an order of magnitude better than those of previous missions. The assembly of the HXD-II completed in January 2004, followed by a series of pre-launch qualification tests. As a result, the design goals of the HXD-II have been met. These include; a background level of 5 x 10^-6 counts/s/keV/cm² at 200 keV for GSO and 1 x 10^-5 counts/s/keV/cm² at 30 keV for PIN; energy resolutions of 2.9 keV (PIN diode, at 59.5 keV) and 10% (GSO scintillator, at 662 keV); and low energy thresholds of 10 keV for PIN diodes and 30 keV for GSO scintillators. The measured background predicts a continuum sensitivity of a few x 10^-6 photons/s/keV/cm². Anti-Counter units surrounding the HXD-II provide 50 keV-5 MeV information on gamma-ray bursts and bright X-ray transients.