MAGNETIC FIELD SHIELDING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a magnetic field shielding device with high performance through the use of sheets with high magnetic permeability. SOLUTION: A plurality of sheets with high magnetic permeability are arranged by partial superimposition on a plurality of non-magnetic cylindrical members which are disposed by concentrically enclosing a first direction axis to have a hollow part. The most internal cylindrical member is provided with first and second openings 41 and 42 at one end and the other end in the first direction and with a third opening 43 which puts through the plurality of cylindrical members in a vertical direction with respect to the first direction axis and where a cryostat for keeping low temperature in pluralities of SQUID flux meters is inserted. A component in the vertical direction concerning the first direction in an extraneous magnetic field is shielded in the internal space of the most inner cylindrical member. Thus, the light and small magnetic field shielding device is provided at a low cost.