Direct-current superconducting quantum interference devices for the readout of metallic magnetic calorimeters. (12th February 2015)

• Record Type: Journal Article
• Authors: Kempf, S; Ferring, A; Fleischmann, A; Enss, C
• Is Part Of: Superconductor science & technology. Volume 28:Number 4(2015:Apr.)
• Publication Date: 2015-02-12
• Subjects: metallic magnetic calorimeters -- direct-current superconducting quantum interference devices -- 1/f noise -- low-temperature microcalorimeters -- SQUID design; 85.25.Dq -- 07.07.Df; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/0953-2048/28/4/045008
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: In this paper we analyze the influence of the coupled energy sensitivity of a superconducting quantum interference device (SQUID) on the energy resolution of metallic magnetic calorimeters. From this, we derive an upper limit on the readout noise that still allows for the readout of detectors with sub-eV energy resolution. Furthermore, we present two dc-SQUID designs, namely a first-stage SQUID and an N -SQUID series array, that are suited for the readout of high-resolution detectors. We show that fabricated SQUIDs have a noise performance that is competitive to the best state-of-the-art dc-SQUIDs. For the first-stage SQUIDs, we found a correlation between the noise exponent α and the noise prefactor (1 Hz). Using both kind of SQUIDs we have built a two-stage dc-SQUID configuration. We show that this setup allows for the readout of x-ray detectors with a resolving power .