Combined shim and bore cooling assembly

An arrangement for shimming a background magnetic field of a cylindrical superconducting magnet for a magnetic resonance imaging apparatus, having a cylindrical outer vacuum chamber (OVC) bore tube, with rails on the OVC bore tube and shim trays containing shim elements mounted between respective rails, said arrangement comprising:

• the rails having grooves that accommodate respective edges of respective shim trays;
• an interference fit between a shim tray and at least one of the respective groove;
• at least some of the rails having a passageway, said passageways being connected by conduits into a coolant circuit for circulation of a coolant fluid therethrough;
• and
• the rails and the shim tray being at least partially constructed of a thermally conductive material, and being in thermal contact with one another and the OVC bore tube, causing the coolant fluid to stabilize a temperature of the OVC bore tube, the shim tray and the shim elements.