White noise performance of integrated DC SQUID susceptometers in high magnetic fields

Author

Stawiasz, K.G. ; Ketchen, M.B. ; Narasimhan, L.R.

Author_Institution

IBM Thomas J. Watson Res. Center, Yorktown Heights, NY, USA

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

3230

Lastpage

3232

Abstract

We have characterized the white noise performance of integrated DC SQUID susceptometers in magnetic fields up to 400 G. The field is applied in the plane of the tunnel junctions and pickup loops. For 1 /spl mu/m diameter junctions, the noise does not increase significantly as the field is increased to 125 G. Further increase of the applied field results in higher noise until approximately 200 G where the critical current of the junctions is at a minimum. The noise then improves to approximately 4 times the zero field value at the maximum of the first lobe of the single junction interference pattern. We have also measured the noise of a SQUID with 0.6 /spl mu/m junctions and found no increase up to 250 G.<>

Keywords

SQUID magnetometers; superconducting device noise; white noise; 0.6 micron; 1 micron; 125 to 400 G; critical current; integrated DC SQUID susceptometers; interference pattern; magnetic fields; pickup loops; tunnel junctions; white noise; Coils; Magnetic field measurement; Magnetic fields; Magnetic noise; Magnetic susceptibility; Noise measurement; Nuclear magnetic resonance; Performance evaluation; SQUIDs; White noise;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403279

Filename

403279