Abstract: There is provided a method of joining a first member made of a niobium titanium alloy to a second member. The method comprises abutting a respective surface of each of the first member and the second member together to form an interface therebetween; providing a molten active solder at a surface of at least the first member at the interface and thermally activating the molten active solder; mechanically agitating the molten active solder so as to cause the molten solder to adhere to the first and second members and form a continuous body of molten solder linking the first and second; and causing the continuous body to solidify thereby forming a solder joint between the first and second members.

Abstract: A pulse tube refrigerator (PTR) comprising a pedestal head and a regenerator tube assembly is provided having particular application in cooling a Magnetic Resonance Imaging system. The PTR comprises a pedestal head and at least one cooled stage, the at least one cooled stage being mounted to a distal end, with respect to the pedestal head, of each of an associated regenerator tube and an associated pulse tube, the associated regenerator tube and associated pulse tube together providing pressurized coolant gas to the at least one cooled stage, wherein the associated regenerator tube and the associated pulse tube are elongate along substantially parallel axes; and further arranged, wherein, the displacements of the distal ends of each of the associated regenerator tube and the associated pulse tube in response to the cyclical changes in coolant pressure, are substantially the same when the pulse tube refrigerator is in use.

Abstract: An assembly for operating a cryocooler pedestal is provided. The assembly is operable when in use to provide a cryocooler pedestal with cyclical gaseous connection to high pressure and low pressure gas supply lines, and has a return conduit through which gas is caused to flow from the cryocooler pedestal into the low pressure supply line. The assembly further comprises a dispersion chamber adjacent the return conduit and in flow communication therewith through a plurality of orifices so as to reduce acoustic noise. The assembly has particular application in cooling a Magnetic Resonance Imaging system.

Abstract: A pulse tube refrigerator (PTR) comprising a pedestal head and a regenerator tube assembly is provided having particular application in cooling a Magnetic Resonance Imaging system. The PTR comprises a pedestal head and at least one cooled stage, the at least one cooled stage being mounted to a distal end, with respect to the pedestal head, of each of an associated regenerator tube and an associated pulse tube, the associated regenerator tube and associated pulse tube together providing pressurised coolant gas to the at least one cooled stage, wherein the associated regenerator tube and the associated pulse tube are elongate along substantially parallel axes; and further arranged, wherein, the displacements of the distal ends of each of the associated regenerator tube and the associated pulse tube in response to the cyclical changes in coolant pressure, are substantially the same when the pulse tube refrigerator is in use.

Abstract: An assembly for operating a cryocooler pedestal is provided. The assembly is operable when in use to provide a cryocooler pedestal with cyclical gaseous connection to high pressure and low pressure gas supply lines, and has a return conduit through which gas is caused to flow from the cryocooler pedestal into the low pressure supply line. The assembly further comprises a dispersion chamber adjacent the return conduit and in flow communication therewith through a plurality of orifices so as to reduce acoustic noise. The assembly has particular application in cooling a Magnetic Resonance Imaging system.