SQUID instruments and shielding for low-level magnetic measurements
- 1 February 1977
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 48 (2), 702-710
- https://doi.org/10.1063/1.323659
Abstract
We have used a thick‐walled aluminum enclosure to provide low‐frequency shielding for biomagnetic studies with SQUID magnetic gradiometers. The shield provides an attenuation proportional to frequency above 1/3 Hz. A 24‐hole fractional‐turn SQUID gradiometer has been used in the enclosure to carry out studies of magnetoencephalography on humans. An ’’asymmetric’’ configuration for a second‐derivative gradiometer has been developed which provides a significant increase in sensitivity and resolution over more conventional symmetric arrays.Keywords
This publication has 11 references indexed in Scilit:
- The human magnetoencephalogram: some EEG and related correlationsElectroencephalography and Clinical Neurophysiology, 1976
- Visually Evoked Magnetic Fields of the Human BrainScience, 1975
- TESTS OF CRYOGENIC SQUID FOR GEOMAGNETIC FIELD MEASUREMENTSGeophysics, 1975
- Measurements of the magnetic fields produced by the human heart, brain, and lungsIEEE Transactions on Magnetics, 1975
- A superconducting second-derivative gradiometerIEEE Transactions on Magnetics, 1974
- Technical notejpme, 1974
- Portable helium dewars for use with superconducting magnetometersCryogenics, 1973
- Sensitivity Enhancement of Superconducting Quantum Interference Devices through the Use of Fractional-Turn LoopsJournal of Applied Physics, 1971
- The magnetic heart vectorAmerican Heart Journal, 1970
- Quantum interference magnetometry and thermal noise from a conducting environmentPhysics Letters A, 1968