A Low-Noise Seven-Channel DC SQUID Magnetometer for Brain Research

Matti Kajola, Seppo Ahlfors, Antti Ahonen, Jari Hällström, Jukka Knuutila, Olli V. Lounasmaa, Claudia Tesche, Visa Vilkman

Research output: Contribution to journalArticleScientificpeer-review

Abstract

The design, construction, and performance of a high-sensitivity DC SQUID magnetometer, covering a circular area of 93 mm diameter, is described. The device, now used routinely in our brain research, comprises seven asymmetric first-order gradiometers, located on a spherical surface of 125 mm radius and with the symmetry axis tilted 30° in respect to the vertical. The overall field sensitivity of the system, measured inside our magnetically shielded room, is 5 - 6 fT/√Hz, mainly caused by thermal noise in the radiation shields of the dewar.

Original languageEnglish
Pages (from-to)1555-1556
Number of pages2
JournalJapanese Journal of Applied Physics
Volume26
Issue numberS3-2
DOIs
Publication statusPublished - Jan 1987
MoE publication typeA1 Journal article-refereed

Fingerprint

Dewars
gradiometers
Thermal noise
SQUIDs
thermal noise
Magnetometers
low noise
magnetometers
rooms
brain
Brain
coverings
direct current
Radiation
radii
sensitivity
symmetry
radiation

Cite this

Kajola, M., Ahlfors, S., Ahonen, A., Hällström, J., Knuutila, J., Lounasmaa, O. V., ... Vilkman, V. (1987). A Low-Noise Seven-Channel DC SQUID Magnetometer for Brain Research. Japanese Journal of Applied Physics, 26(S3-2), 1555-1556. https://doi.org/10.7567/JJAPS.26S3.1555
Kajola, Matti ; Ahlfors, Seppo ; Ahonen, Antti ; Hällström, Jari ; Knuutila, Jukka ; Lounasmaa, Olli V. ; Tesche, Claudia ; Vilkman, Visa. / A Low-Noise Seven-Channel DC SQUID Magnetometer for Brain Research. In: Japanese Journal of Applied Physics. 1987 ; Vol. 26, No. S3-2. pp. 1555-1556.
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Kajola, M, Ahlfors, S, Ahonen, A, Hällström, J, Knuutila, J, Lounasmaa, OV, Tesche, C & Vilkman, V 1987, 'A Low-Noise Seven-Channel DC SQUID Magnetometer for Brain Research', Japanese Journal of Applied Physics, vol. 26, no. S3-2, pp. 1555-1556. https://doi.org/10.7567/JJAPS.26S3.1555

A Low-Noise Seven-Channel DC SQUID Magnetometer for Brain Research. / Kajola, Matti; Ahlfors, Seppo; Ahonen, Antti; Hällström, Jari; Knuutila, Jukka; Lounasmaa, Olli V.; Tesche, Claudia; Vilkman, Visa.

In: Japanese Journal of Applied Physics, Vol. 26, No. S3-2, 01.1987, p. 1555-1556.

Research output: Contribution to journalArticleScientificpeer-review

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AU - Lounasmaa, Olli V.

AU - Tesche, Claudia

AU - Vilkman, Visa

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