Miniature Thin-Film SQUID Susceptometer for Magnetic Microcalorimetry and Thermometry

Author

Boyd, Stephen T P ; Kotsubo, Vincent ; Cantor, Robin ; Theodorou, Alexander ; Hall, J. Ad

Author_Institution

Dept. of Phys. & Astron., Univ. of New Mexico, Albuquerque, NM, USA

Volume

19

Issue

3

fYear

2009

fDate

6/1/2009 12:00:00 AM

Firstpage

697

Lastpage

701

Abstract

We have developed a miniature thin-film SQUID susceptometer for research in magnetic microcalorimetry and miniature magnetic thermometry. We have previously reported measurements at 4 K characterizing performance of the first generation of this device using modulation-based flux-locked feedback electronics and at ~50 mK using a spherical superconducting test sample. Here we describe the design, fabrication, and new measurements of the second generation of the device using two-stage SQUID amplification to characterize the improved noise, bandwidth, persistence switch and field coil performance. The device now meets or exceeds all requirements for magnetic microcalorimetry sensor testing, achieving noise of ~ 0.75 muPhi₀/radicHz and bandwidth ~1.2 MHz near 50 mK, and trapping and stably holding magnetizing field of at least 5.9 mT.

Keywords

SQUID magnetometers; calorimetry; superconducting coils; thermometers; thin film devices; field coil performance; magnetic microcalorimetry; magnetic microcalorimetry sensor; magnetometers; miniature magnetic thermometry; miniature thin-film SQUID susceptometer; modulation-based flux-locked feedback electronics; two-stage SQUID amplification; Detectors; SQUID magnetometers; superconducting switches;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2009.2018190

Filename

5153013