Design of a 7-channel DC-SQUID gradiometer for brain research

A. I. Ahonen (Corresponding author), J. K. Hallstrom, M. J. Kajola, J. E. Knuutila, C. D. Tesche, V. A. Vilkman

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

4 Citations (Scopus)


The design of a 7-channel DC-SQUID gradiometer system for brain research is discussed. The system is based on high-quality DC-SQUIDs made by IBM. The flux transformer system consists of seven identical wire-wound asymmetric axial first order gradiometers in a hexagonal array. The pickup loop diameter is 20 mm, and the base length 60 mm. The lower ends of the gradiometers are on the curved bottom surface of a dewar with a 125 mm radius of curvature. The diameter of the active measurement area is 94 mm. The DC-SQUIDs are matched to FET preamplifiers using superconducting resonant transformers. The preamplifiers are connected to detector/controller units located in a separate RF-shielded cabinet outside of the magnetically shielded room. The digitized outputs of the detectors are sent to a set of signal processors via a fiber optic link.

Original languageEnglish
Title of host publicationProceedings of the International Cryogenic Engineering Conference, ICEC 11
EditorsGustav Klipping, Ingrid Klipping
Number of pages5
ISBN (Print)0-408-01258-7
Publication statusPublished - 1 Dec 1986
MoE publication typeA4 Article in a conference publication


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