Energy resolution and high count rate performance of superconducting tunnel junction x-ray spectrometers

We present experimental results obtained with a cryogenically cooled, high-resolution x-ray spectrometer based on a 141 μm×141 μm Nb-Al-Al2O3-Al-Nb superconducting tunnel junction (STJ) detector in a demonstration experiment. Using monochromatized synchrotron radiation we studied the energy resolution of this energy-dispersive spectrometer for soft x rays with energies between 70 and 700 eV and investigated its performance at count rates up to nearly 60 000 cps. At count rates of several 100 cps we achieved an energy resolution of 5.9 eV (FWHM) and an electronic noise of 4.5 eV for 277 eV x rays (the energy corresponding to C K). Increasing the count rate, the resolution 277 eV remained below 10 eV for count rates up to ∼10 000 cps and then degraded to 13 eV at 23 000 cps and 20 eV at 50 000 cps. These results were achieved using a commercially available spectroscopy amplifier with a baseline restorer. No pile-up rejection was applied in these measurements. Our results show that STJ detectors can operate ...

[1]  N. E. Booth.  Quasiparticle trapping and the quasiparticle multiplier , 1987 .

[2]  J. Beeman,et al.  High‐Resolution, Broad‐Band Microcalorimeters for X‐Ray Microanalysis , 1996 .

[3]  D. Twerenbold,et al.  Cryogenic particle detectors , 1996 .

[4]  M. Kurakado,et al.  Possibility of high resolution detectors using superconducting tunnel junctions , 1982 .

[5]  Paul L. Richards,et al.  Development of an adiabatic demagnetization refrigerator for SIRTF , 1990 .

[6]  R. Ruby,et al.  A simple and robust niobium Josephson junction integrated circuit process , 1991 .

[7]  D. J. Goldie,et al.  Statistical noise due to tunneling in superconducting tunnel junction detectors , 1994 .

[8]  Lederer,et al.  Response of niobium-based superconducting tunnel junctions in the soft-x-ray region 0.15-6.5 keV. , 1996, Physical review. B, Condensed matter.

[9]  R. Bachrach,et al.  The SSRL ultrahigh vacuum grazing incidence monochromator: Design considerations and operating experience , 1978 .

[10]  H. Netel,et al.  High-resolution superconducting X-ray spectrometers with aluminum trapping layers of different thicknesses , 1995, IEEE Transactions on Applied Superconductivity.

[11]  G. Hilton,et al.  X‐ray detection using a superconducting transition‐edge sensor microcalorimeter with electrothermal feedback , 1996 .

[12]  B. L. Henke,et al.  X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E = 50-30,000 eV, Z = 1-92 , 1993 .

[13]  Oswald H. W. Siegmund,et al.  EUV, X-ray, and gamma-ray instrumentation for astronomy VII : 7-9 August 1996, Denver, Colorado , 1995 .

[14]  L. J. Hiller,et al.  High-resolution superconducting X-ray spectrometers with an active area of 282 /spl mu/m/spl times/282 /spl mu/m , 1997, IEEE Transactions on Applied Superconductivity.

[15]  David H. Lumb,et al.  Soft x-ray (50-1800 eV) measurements of niobium superconducting tunnel junctions , 1995, Optics & Photonics.

[16]  N. E. Booth,et al.  Superconducting particle detectors , 1996 .

[17]  S. Moseley,et al.  Thermal calorimeters for high resolution X-ray spectroscopy , 1993 .

[18]  Simon E. Labov,et al.  Temperature dependence of a superconducting tunnel junction x-ray detector , 1995, Optics & Photonics.

[19]  Simon E. Labov,et al.  Analysis of pulse shape from a high-resolution superconducting tunnel junction X-ray spectrometer , 1996 .

[20]  Simon E. Labov,et al.  Energy-resolving superconducting x-ray detectors with charge amplification due to multiple quasiparticle tunneling , 1993 .

[21]  D. J. Goldie,et al.  Single optical photon detection with a superconducting tunnel junction , 1996, Nature.

[22]  M. Frank,et al.  Low-energy response of superconducting tunnel junction X-ray spectrometers , 1995, IEEE Transactions on Applied Superconductivity.