Title :
High resolution tunnel junction extreme ultraviolet detectors limited by quasiparticle counting statistics
Author :
Friedrich, S. ; Le Grand, J.B. ; Hiller, L.J. ; Kipp, J. ; Frank, M. ; Labov, S.E. ; Cramer, S.P. ; Barfknecht, A.T.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
fDate :
6/1/1999 12:00:00 AM
Abstract :
Superconducting tunnel junctions (STJs) can be used as high-resolution high-count rate photon detectors. They are based on the measurement of the excess quasiparticle tunneling current caused by the absorption of a photon in one of the junction electrodes. We have fabricated Nb-Al-AlO/sub x/-Al-Nb tunnel junction detectors with different sizes and characterized them in synchrotron experiments. We present a study of the detector performance in the energy band between 50 and 1000 eV. For photon energies below 70 eV, the intrinsic device resolution of the best STJ devices agrees with the theoretical limit set by the statistics of the charge generation and tunneling processes.
Keywords :
X-ray detection; X-ray spectrometers; aluminium; aluminium compounds; niobium; photon counting; superconducting junction devices; superconducting particle detectors; ultraviolet detectors; 50 to 1000 eV; Nb-Al-AlO-Al-Nb; Nb-Al-AlO/sub x/-Al-Nb; X-ray detectors; excess quasiparticle tunneling current; high resolution; high-count rate photon detectors; intrinsic device resolution; photon absorption; quasiparticle counting statistics; soft X-ray spectrometers; superconducting tunnel junctions; tunnel junction EUV detectors; Current measurement; Detectors; Electrodes; Electromagnetic wave absorption; Josephson junctions; Semiconductor counters; Superconducting photodetectors; Synchrotrons; Tunneling; Ultraviolet sources;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
