Analysis of novel superconducting magnetometer with superior noise and coupling properties. Interim report

Technical Report · Sun Nov 01 00:00:00 EST 1981

OSTI ID:5613948

Tesche, C D

There is considerable interest in the development of extremely sensitive superconducting magnetometers for the detection of changes in magnetic field intensity. The most sensitive detectors developed up to this time are thin film dc SQUID magnetometers. The dc SQUID consists of a superconducting loop interrupted by two Josephson junctions. If the junctions are biased near the critical current by an externally applied dc bias current, the voltage across the junctions becomes a sensitive function of the flux threading the loop. Thus, the dc SQUID acts like a flux to voltage transducer. The resolution of the dc SQUID magnetometer is determined predominately by three factors. First, the Josephson junctions employed in the device must be non-hysteretic. As a result, the thin film tunnel junctions typically used in the device are externally shunted by a normal resistance. The Johnson noise associated with this resistance produces fluctuations in the voltage across the SQUID.

• Research Organization: LuTech, Inc., Berkeley, CA (USA)
• OSTI ID: 5613948
• Report Number(s): AD-A-129624/3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SQUID DEVICES
PERFORMANCE
CAPACITANCE
DIRECT CURRENT
ELECTRIC COILS
EQUIVALENT CIRCUITS
FUNCTIONS
HYSTERESIS
JOSEPHSON JUNCTIONS
MAGNETIC FIELDS
MAGNETOMETERS
NOISE
SENSITIVITY
SUPERCONDUCTORS
THIN FILMS
TRANSDUCERS
TRANSFORMERS
CURRENTS
ELECTRIC CURRENTS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
EQUIPMENT
FILMS
FLUXMETERS
JUNCTIONS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
PHYSICAL PROPERTIES
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
420201* - Engineering- Cryogenic Equipment & Devices