ACTIVE SHIELD SUPERCONDUCTIVE MAGNET SYSTEM WITH Z2 SHIM

摘要

PROBLEM TO BE SOLVED: To reduce the space required for a Z2 shim coil wound radially inside a magnet coil to attain optimization of the Z2 shim, using a simple means, without being affected by a disturbance caused by a fluctuated external magnetic field. SOLUTION: The shim coil system is provided with a radial-directional inside shim coil pair Si separated inductively from a magnet system to generate a magnetic field of which the z-component changes according to the expressionΔH0+c2.z2 (c2 = constant) in a working volume, and a radial-directional outside shim coil pair Sa separated inductively from the magnet system to generate a uniform magnetic field -ΔH0 in the working volume. By this constitution, a compact Z2 shim system not affected by the disturbance caused by the fluctuated external magnetic field is provided while saving the space in a site of the magnet coil.