NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Development of High Resolution Mirrors and Cd-Zn-Te Detectors for Hard X-ray AstronomyWe describe the fabrication and implementation of a high-resolution conical, grazing- incidence, hard X-ray (20-70 keV) telescope. When flown aboard stratospheric balloons, these mirrors are used to image cosmic sources such as supernovae, neutron stars, and quasars. The fabrication process involves generating super-polished mandrels, mirror shell electroforming, and mirror testing. The cylindrical mandrels consist of two conical segments; each segment is approximately 305 mm long. These mandrels are first, precision ground to within approx. 1.0 micron straightness along each conical segment and then lapped and polished to less than 0.5 micron straightness. Each mandrel segment is the super-polished to an average surface roughness of approx. 3.25 angstrom rms. By mirror shell replication, this combination of good figure and low surface roughness has enabled us to achieve 15 arcsec, confirmed by X-ray measurements in the Marshall Space Flight Center 102 meter test facility. To image the focused X-rays requires a focal plane detector with appropriate spatial resolution. For 15 arcsec optics of 6 meter focal length, this resolution must be around 200 microns. In addition, the detector must have a high efficiency, relatively high energy resolution, and low background. We are currently developing Cadmium-Zinc-Telluride fine-pixel detectors for this purpose. The detectors under study consist of a 16x16 pixel array with a pixel pitch of 300 microns and are 1 mm and 2 mm thick. At 60 keV, the measured energy resolution is around 2%.
Document ID
20030001973
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Ramsey, Brian D.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Speegle, Chet O.
(Raytheon Information Technology and Scientific Services Huntsville, AL United States)
Gaskin, Jessica
(Alabama Univ. Huntsville, AL United States)
Sharma, Dharma
(NASA Marshall Space Flight Center Huntsville, AL United States)
Engelhaupt, Darell
(Alabama Univ. Huntsville, AL United States)
Six, N. Frank
Date Acquired
August 21, 2013
Publication Date
January 1, 2002
Subject Category
Optics
Meeting Information
Meeting: Optical Society of America: Optics in the Southeast: Topical Meeting and Tabletop Exhibit
Location: Huntsville, AL
Country: United States
Start Date: October 24, 2002
End Date: October 25, 2002
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available