Collection Item Summary:
This is an imaging x-ray detector built by Steve Murray in the early 1970s as part of his PhD research program in 2-dimensional imaging techniques. Under the direction of Riccardo Giacconi, he laboriously hand wound this breadboard model to show that his "cross-grid" design was viable. The copper wire grid is wound in two orthogonal layers and is part of an electronic circuit that is sensitive to incoming electrons. To make it detect x-rays, Murray placed what is called a microchannel plate on top of the grid. Incoming X-rays from a hot source would first hit the front of the microchannel plate and be converted into electrons. The microchannel plate then amplified the resulting electronic charge producing a stream that then hit the dense grid of very fine wires on the detector. The intersections of the wires in the two layers define the x and y coordinates of the charge stream. The resulting signal is used to construct images of the sources of original X-ray pattern. The proof of principle provided by this breadboard detector led to the high resolution X-ray imagers used on orbiting X-ray observatories including HEAO-2 (Einstein), ROSAT, and AXAF (Chandra).
It was transferred to NASM from SAO in 2002.
Collection Item Long Description:
National Air and Space Museum
Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum
Smithsonian Astrophysical Observatory
Transferred from the Smithsonian Astrophysical Observatory, Harvard University.
3-D: 12.7 × 10.2 × 2.2cm (5 × 4 × 7/8 in.)
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National Air and Space Museum Collection
Country of Origin
United States of America