CyroSQUID: a SQUID-based magnetic-field sensor. Technical report No. 3 (Final), 15 August 1984-30 November 1987

Technical Report · Tue Mar 15 00:00:00 EST 1988

OSTI ID:6778576

Williamson, S J; Kaufman, L

A new type of neuromagnetometer was developed to enhance the capability for measuring the magnetic field of the human brain. This system - known as CryoSQUID - results from the marriage of two advanced technologies: a refrigerator incorporating closed-cycle operation of a pair of cryocoolers and a sensor incorporating the superconducting quantum interference device (SQUID). The apparatus is relatively small and requires no supply of liquid helium for initial cooling or operation. Only a source of electrical power is needed. Each sensor relies on a detection coil wound in the geometry of a second-order gradiometer so as to minimize the effects of ambient magnetic noise found in typical unshielded environments. The intrinsic noise level of CryoSQUID is comparable to a magnetic field sensitivity of 20 femtotesla within a one-hertz bandwidth. Residual noise at 1.2 Hz and its harmonics, contributed by the displacer in the Gifford-McMahon cooler, is virtually eliminated in real time by an adaptive filter run on a personal computer.

• Research Organization: New York Univ., NY (USA). Neuromagnetism Lab.
• OSTI ID: 6778576
• Report Number(s): AD-A-194237/4/XAB
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BRAIN
MAGNETIC FIELDS
MAGNETOMETERS
SQUID DEVICES
BACKGROUND NOISE
CRYOGENICS
PROGRESS REPORT
SUPERCONDUCTIVITY
BODY
CENTRAL NERVOUS SYSTEM
DOCUMENT TYPES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUXMETERS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
NERVOUS SYSTEM
NOISE
ORGANS
PHYSICAL PROPERTIES
SUPERCONDUCTING DEVICES
420201* - Engineering- Cryogenic Equipment & Devices