Superconducting Sn/Sn-oxide/Sn tunneling junctions as high-resolution x-ray detectors

Journal Article · Thu Jan 01 04:00:00 EST 1987 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.338855· OSTI ID:7099723

Twerenbold, D; Zehnder, A

In a superconducting detector, the energy resolution is expected to be superior than in a semiconductor detector, owing to the thousand times smaller energy gap ..delta... The performance of Sn/Sn-oxide/Sn tunneling junctions (operated in the Giaever mode at T = 0.32 K) exposed to 6-keV x-ray photons of a /sup 55/Fe source is presented. The best energy resolution observed is 67 eV (FWHM). Extrapolating to vanishing electronic noise, an intrinsic resolution of 0.7% (FWHM) is obtained. This is an order of magnitude worse than expected from the statistics of the 2.5 x 10/sup 6/ primary electron charges produced, and is believed to be due to geometrical effects in the films. The energy response of the detector is nonlinear, owing to the self-recombination of the free charge carriers. At a fixed bias voltage, the pulses generated in either film of the junction were observed to have the same sign. If the junctions are evaporated onto a silicon substrate, most of the pulses originate, via phonon backscattering, from x-ray photons interacting in the substrate. Quasiparticle diffusion is essential in explaining the observed data.

• Research Organization: Swiss Institute for Nuclear Research, CH-5234 Villigen, Switzerland
• OSTI ID: 7099723
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 61:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKSCATTERING
CHALCOGENIDES
DETECTION
ELEMENTS
ENERGY GAP
ENERGY RESOLUTION
JUNCTIONS
METALS
OPERATION
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
RADIATION DETECTION
RESOLUTION
SCATTERING
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
TIN
TIN COMPOUNDS
TIN OXIDES
TUNNEL EFFECT
X-RAY DETECTION