THE DEVELOPMENT OF A HIGH-T-C MAGNETOCARDIOGRAPHY SYSTEM FOR UNSHIELDED ENVIRONMENT

A modular, 9-channel high-T-c SQUID system for magnetocardiography (MC G) was developed and tested in unshielded environment. Galvanically-co upled magnetometers made from Y-Ba-Cu-O films, with intrinsic white no ise levels as low as 70 fT/root Hz, are used as SQUID sensors. In unsh ielded environment, a noise level of about 1 pT/root Hz for each chann el was achieved using an active noise compensation system. A new digit al planar gradiometer is proposed. First magnetocardiograms recorded i n unshielded environment are presented.