| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1508282 | Cryogenics | 2008 | 7 Pages |
Abstract
A cryocooler-cooled low-Tc SQUID gradiometer system was designed and constructed. It is based on a 4 K GM-cooler that is positioned several meters from the measuring head containing the SQUID sensors. The cooling power is transported by means of a circulating helium flow. Thus, there are three main components: the cooler vessel, the measuring head and the connecting flow-line.In stable operation, the SQUID and gradiometric pick-up loop are about 4.3 K. The overall heat loads to the cooler 1st and 2nd stages are estimated at 17 W and 0.3 W, respectively. The overall system noise was about 10 fT/√Hz although a number of peaks were observed in the spectrum. As an example, an adult heart beat was recorded.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
A.P. Rijpma, H.J.G. Krooshoop, M.W. Lefevere, E.P. van Leeuwen, H.J. Holland, B. ten Haken, H.J.M. ter Brake,