HEXITEC: A next generation hard X-ray Detector for Solar Observations

SH43B-2457
HEXITEC: A next generation hard X-ray Detector for Solar Observations

Thursday, 17 December 2015

Poster Hall (Moscone South)

Marco Panessa, NASA Goddard Space Flight Center, Greenbelt, MD, United States

High angular resolution HXR optics require detectors with a large number of

fine pixels in order to adequately sample the telescope point spread function

(PSF) over the entire field of view. Recent developments at the Rutherford Appleton

Laboratory (RAL) have resulted in a new hard X-ray (HXR) detector system with the

smallest independent pixels currently available, 250 microns.

This matches perfectly with the best angular resolution currently achievable by

HXR focusing optics which is about 5 arcsec (FWHM). For a SMEX mission with a 15 meter

focal length each pixel would cover an angular size of about 3 arcsec thereby

subsampling the PSF. Dubbed HEXITEC, for High Energy X-Ray Imaging Technology, this Application

Specific Integrated Circuit (ASIC), can be bonded to 1- or 2- mm-thick

Cadmium Telluride (CdTe) or Cadmium-Zinc-Telluride (CZT) which provide high

efficiency in the HXR region, good energy resolution, low background, low power, and low sensitivity

to radiation damage. For solar observations, the ability to handle high

counting rates is also extremely desirable. This ASIC can read each pixel 10,000

times per second. The NASA Marshall Space Flight Center (MSFC)

and the Goddard Space Flight Center (GSFC) has been working with RAL over

the past few years to develop these detectors to be used with HXR focusing

telescopes. We present recent progress on this development effort and

its capabilities as applied to solar observations.