Abstract
Superconducting tunnel junctions can be used as high resolution x-ray and gamma-ray detectors. Until recently, most results were from detectors that consisted of niobium and aluminum thin films deposited on insulating substrates. Typically Nb films with thicknesses of several hundred nanometers are used as absorbers. These thin film devices inherently suffer from poor quantum efficiency. To increase this efficiency a foil or a single crystal, which can be thicker and can have a larger area than the thin films, can be used as the superconducting absorber. We are working on using ultra-pure, high-Z, superconducting crystals as the x-ray and gamma-ray absorbers. We are planning to fabricate a detector which uses a 10 micrometer-thick Ta crystal as the absorber, which will have a quantum efficiency of greater than 99% at 6 keV. As a test of the different processing steps we fabricated Al/AlOx/Al superconducting tunnel junctions on top of a 30 micrometer thick Al foil. In this paper several of the fabrication issues involved are presented as well as the first results from the Al foil test devices.
Original language | English (US) |
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Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |
Editors | Oswald H. Siegmund, John V. Vallerga |
Pages | 244-248 |
Number of pages | 5 |
Volume | 2518 |
State | Published - Dec 1 1995 |
Externally published | Yes |
Event | EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy VI - San Diego, CA, USA Duration: Jul 12 1995 → Jul 14 1995 |
Other
Other | EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy VI |
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City | San Diego, CA, USA |
Period | 7/12/95 → 7/14/95 |
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics