High-resolution X-ray detectors with high-speed SQUID readout of superconducting tunnel junctions

Frank, Matthias; Mears, C. A.; Labov, S. E.; Azgui, F.; Lindeman, M. A.; Hiller, L. J.; Netel, H.; Barfknecht, A.T.

doi:10.1016/0168-9002(95)01044-0

Cited by 45 publications

(17 citation statements)

References 4 publications

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“…Since the separation between the main peak and satellite is --~13 eV for Fe complexes, a detector with 10 3 energy resolution would be sufficient for measuring spin-polarized spectra. The development of ultra-high-energy-resolution detectors, such as the bolometer (Le Gros et al, 1995) and the superconducting tunnel junction detector (Frank et al, 1996), may eventually eliminate the whole crystal spectrometer for spin-polarized studies. It is, however, essential to have spectrometer resolution which is better than l eV in order to utilize the chemical shifts (,-~1 eV) in mixed-valence and mixed-spin-state clusters for siteselective XAS.…”

Section: Future Prospectsmentioning

confidence: 99%

High-Resolution X-ray Fluorescence and Excitation Spectroscopy of Metalloproteins

Wang¹,

Grush²,

Froeschner³

et al. 1997

J Synchrotron Radiat

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A spectrograph has been developed with sufficient efficiency to make high-resolution fluorescence experiments on metalloproteins possible. The resolution of this spectrometer can reach 0.45 eV at 7.1 keV emission energy. The focus images of this multiple curved-crystal array spectrometer are presented. The chemical sensitivity of K/4 emission spectra can be used to identify chemical states, and the spin-polarized near-edge structure provides a new measure of the spin density. The high-resolution fluorescence metalloprotein studies should become routine with third-generation synchrotron facilities, and the strength of both site and spin selectivity should complement the structural information from other spectroscopies.

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Section: Future Prospectsmentioning

confidence: 99%

High-Resolution X-ray Fluorescence and Excitation Spectroscopy of Metalloproteins

Wang¹,

Grush²,

Froeschner³

et al. 1997

J Synchrotron Radiat

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“…In Fig. 3a, we show a simulated pulse for an underdamped configuration, where R, is set to 20 R, and the bias resistor is set to 0.044 R. This is the configuration we used earlier [5], [17] to measure the current in a 100 pm x 100 pm junction. When this same configuration is used for a larger, 282 pm x 282 pm junction, oscillations result as shown.…”

Section: Readout Electronicsmentioning

confidence: 99%

High-resolution superconducting X-ray spectrometers with an active area of 282 μm×282 μm

Mears

Labov

Frank

et al. 1997

IEEE Trans. Appl. Supercond.

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Superconducting tunnel junctions coupled to superconducting absorbers may be used as high-resolution, high-efficiency X-ray s p e ctrometers. We have tested devices with niobium Xray absorbing layers coupled to aluminum layers that serve as quasiparticle traps. In this work we measure the current pulses from a large-area tunnel junction using an amplifier based on an array of 100 SQUIDS. Using this amplifier and a 282 ym x 2 8 2 ym junction, we have measured an energy resolution of 19 eV FWHM for 1.5 keV X rays and 21 eV for 2.6 keV X rays. The area of this junction is eight t i m e s the area of any junction previously measured t o have such high energy resolution.

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“…Measuring these signals with a signal-tonoise ratio of 1000 in a =lo0 kHz bandwidth thus requires an input current noise around 0.3 pAIdHz. (Vertically stacked SIS junction detectors or transition edge bolometers can provide larger signal currents, which eases the requirements on electronic noise [3], [4]. However, detectors which are used in double junction configurations will have slower charge collection leading to smaller signal currents.…”

Section: Introductionmentioning

confidence: 99%

“…For low impedance devices, preamplifiers with SQUID input stages offer the best noise performance [3], while FET input stages are superior for device impedances in the ki2 range. A modern low-noise, large-bandwidth preamplifier is the Amptek A250 transresistance amplifier [5].…”

Section: Introductionmentioning

confidence: 99%

Single photon imaging X-ray spectrometers using low noise current preamplifiers with dc voltage bias

Friedrich

Segall

Gaidis³

et al. 1997

IEEE Trans. Appl. Supercond.

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We have developed superconducting single-photon imaging x-ray detectors with an energy resolution of 54 eV at 6 keV and a spatial resolution of 1 pm over an effective length of 40 pm. They utilize a current-sensitive low-noise preamplifier with a dc voltage bias. It has a signal bandwidth of 300 kHz, current noise of i = 0.26 pA/-\IHz and voltage noise of e, = 0.5 nV/?Hz with an input capacitance of 200 pF under operating conditions. Injected pulses with a charge Q = 3.7*106 electrons have been measured with a standard deviation OQ = 3400 electrons, corresponding to an electronic noise of 13 eV at 6 keV.

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High-resolution X-ray detectors with high-speed SQUID readout of superconducting tunnel junctions

Cited by 45 publications

References 4 publications

High-Resolution X-ray Fluorescence and Excitation Spectroscopy of Metalloproteins

High-Resolution X-ray Fluorescence and Excitation Spectroscopy of Metalloproteins

High-resolution superconducting X-ray spectrometers with an active area of 282 μm×282 μm

Single photon imaging X-ray spectrometers using low noise current preamplifiers with dc voltage bias

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