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

Journal Article · Thu Jan 01 00:00:00 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), Vol. 61:1
• Country of Publication: United States
• Language: English

Related Subjects

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