Title :
A Nb single crystal X-ray detector read out by superconductive tunnel junctions
Author :
van den Berg, M.L. ; Kiewlet, F.B. ; Bruijn, M.P. ; Luiten, O.J. ; de Korte, P.A.J. ; Martin, J. ; Huebener, R.P.
Author_Institution :
Space Res. Organ., Utrecht, Netherlands
fDate :
6/1/1999 12:00:00 AM
Abstract :
We have fabricated a prototype imaging X-ray detector, consisting of Al/AlOx/Al/Nb superconductive tunnel junctions sputtered directly on a high purity Nb single crystal with an RRR/spl ap/15000. Such a detector in principle offers a high energy resolution, combined with a high quantum efficiency, a large detection area and imaging capabilities. The quasiparticle collection efficiency and consequently the X-ray response of the detector is still very poor due to the large thickness of the crystal (120 /spl mu/m), but agrees with proximity theory. By irradiation with a focused electron beam of a Low Temperature Scanning Electron Microscope, the spatial and temporal response of the detector has been determined. The derived diffusion coefficient is two orders of magnitude smaller than expected on the basis of the RRR.
Keywords :
X-ray detection; niobium; quasiparticles; readout electronics; scanning electron microscopy; superconducting particle detectors; superconductive tunnelling; Al-AlO-Al; Al/AlOx/Al superconductive tunnel junction; Nb; Nb single crystal X-ray detector; detection area; diffusion coefficient; energy resolution; focused electron beam irradiation; imaging; low temperature scanning electron microscopy; proximity effect; quantum efficiency; quasiparticle collection efficiency; readout electronics; residual resistance ratio; sputtered coating; Electron beams; Energy resolution; High-resolution imaging; Niobium; Optical imaging; Prototypes; Superconductivity; X-ray detection; X-ray detectors; X-ray imaging;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
