Low‐Field Room Built at High‐Field Magnet Lab

A magnetically shielded walk‐in room whose residual field is about 100 nanogauss is now operating at MIT's Francis Bitter National Magnet Laboratory. The room's designer, David Cohen, has recently reported using a point‐contact “SQUID” (superconducting quantum interference device) inside the room to record the magnetic field of the human heart without noise averaging. Cohen also plans to use the room for ac and dc measurements of the magnetic field from the human brain; roughly the brain's field is 1 nanogauss and the heart's peak field is 1 microgauss.