Filler material for magnet resonant system self-shielded gradient coil assemblies

A self-shielded gradient coil assembly, comprising:

• inner and outer gradient coil windings, each of a hollow cylindrical configuration and of respectively smaller and larger inner and outer diameters, disposed in coaxial relationship and defining a hollow annular space between an outer surface of the inner gradient coil winding and an inner surface of the outer gradient coil winding;
• and,
• a filler material, substantially filling the hollow annular space, comprising concrete, wherein the concrete comprises portland cement and a selected aggregate material, wherein the aggregate material comprises a mixture of pumice and latex.

A self-shielded gradient coil assembly, comprising:

• inner and outer gradient coil windings, each of a hollow cylindrical configuration and of respectively smaller and larger inner and outer diameters, disposed in coaxial relationship and defining a hollow annular space between an outer surface of the inner gradient coil winding and an inner surface of the outer gradient coil winding;
• and,
• a filler material, substantially filling the hollow annular space, comprising concrete, wherein the concrete comprises portland cement and a selected aggregate material and wherein the aggregate material is selected from a group consisting of pumice, fly ash and expanded shale materials, and wherein the concrete has been treated with supercritical CO2 while hardening.

A self-shielded gradient coil assembly, comprising:

• inner and outer gradient coil windings, each of a hollow cylindrical configuration and of respectively smaller and larger inner and outer diameters, disposed in coaxial relationship and defining a hollow annular space between an outer surface of the inner gradient coil winding and an inner surface of the outer gradient coil winding;
• and,
• a filler material, substantially filling the hollow annular space, comprising concrete, wherein the concrete comprises standard cement having a specific gravity of approximately 2.27 and a selected aggregate material and wherein the aggregate material is selected from a group consisting of pumice, fly ash and expanded shale materials.