Effect of noise on the performance of rf SQUID magnetometers

Journal Article · Mon Jan 01 04:00:00 EST 1979 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.325645· OSTI ID:6508499

Brunet-Brunol, D; Pascal, D; Duret, D

The various noise contributions of an rf SQUID have been studied. The importance of the noise figure of the rf amplifier has been pointed out by calculation and experiments, particularly by using a cooled GaAs FET preamplifier (noise temperature 25 K at 300 MHz) we have designed. The effects of noise upon the flux-locked loop characteristic have been investigated by introducing the notions of unlocking probability and of unlocking average time; the improvement of performances, especially of the slew rate of the flux-locked system by an increase of the modulation frequency, is limited by the noise.

• Research Organization: Institut d'Electronique Fondamentale, Laboratoire associe au C.N.R.S., Batiment 220, Universite de Paris Sud, 91405 Orsay, France
• OSTI ID: 6508499
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 50:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
ELECTRONIC EQUIPMENT
FEEDBACK
FLUXMETERS
MAGNETIC AMPLIFIERS
MAGNETIC FLUX
MAGNETOMETERS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
NOISE
PERFORMANCE
SQUID DEVICES
SUPERCONDUCTING DEVICES