ACTIVELY SHIELDED, CYLINDRICAL GRADIENT MAGNETIC FIELD COIL APPARATUS WITH PASSIVE RF SHIELDING FOR NMR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a gradient magnetic field coil for use in an MR (magnetic resonance) spectrometer which maximizes the space available in an NMR probe.SOLUTION: In an actively shielded NMR gradient magnetic field coil system, no electrical conductor elements of the gradient magnetic field coil system are present in a hollow cylindrical section along an axial length L1 in a radius range between a minimum inner radius R1gradient of a main gradient magnetic field coil and R1shield, and a passive RF shield 3 is provided that is constructed from at least three electrically interconnected partial sections, of which two partial sections are disposed around the z-axis with a maximum outer radius R1hf, while, between the two partial sections, a third partial section with an axial length L2 and a minimum inner radius R2hf as well as a maximum outer radius R2hf is disposed around the z-axis.