CyroSQUID: A SQUID-Based Magnetic Field Sensor.

Abstract

A new type of neuromagnetometer has been 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.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 15, 1988
Accession Number
ADA194237

Entities

People

  • Lloyd Kaufman
  • S. J. Williamson

Organizations

  • New York University

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Acquisition
  • Adaptive Filters
  • Air Force
  • Compressors
  • Computers
  • Data Acquisition
  • Detection
  • Detectors
  • Filters
  • Magnetic Detection
  • Magnetic Detectors
  • Magnetic Fields
  • Magnetometers
  • Measurement
  • New York
  • Personal Computers
  • Psychology

Fields of Study

  • Physics

Readers

  • Approximation Theory.
  • Electrical Engineering
  • Superconducting Magnet Technology

Technology Areas

  • Quantum Computing
  • Quantum Science - Quantum Dots