Characterization of the Astro-E2 X-ray spectrometer

We present the results of extensive characterization tests of the X-ray Spectrometer (XRS), which will be launched in 2005 as part of the Astro-E2 mission. The XRS will utilize a newly developed 2-D microcalorimeter array of 32 pixels that will provide a resolution of ∼6 eV over the energy range 0.3–10 keV. The detector is characterized by the energy scale and energy resolution, both of which vary with design and operating parameters. We have calibrated the gain scale and energy resolution over a range of operating parameters including bias voltage, temperature, and incident photon flux. We will present the response of the cumulative detector array as well as a measure of the uniformity of the individual pixels. One pixel is physically offset from the array and will be continuously illuminated by a radioactive source in-flight. We will show the accuracy with which this pixel can be used to monitor variations in the focal plane array. Finally, we have illuminated the array with a high-energy continuum source and measured the Hg absorption edges in order to characterize the absorption efficiency of the pixels.