A positioning device configured to position an object, the positioning device including: an object table configured to hold the object; an electromagnetic motor configured to displace the object table, the electromagnetic motor including: a coil assembly mounted to the object table, a superconductor assembly configured to co-operate with the coil assembly to generate a driving force on the object table, and a cryogenic enclosure configured to enclose the superconductor assembly and maintain the superconductor assembly in a superconductive state; a support for supporting the electromagnetic motor; and an electromagnetic support configured to suspend the cryogenic enclosure relative to the support, thereby maintaining a gap between the cryogenic enclosure and the support.

A positioning device configured to position an object, the positioning device including: an object table configured to hold the object; an electromagnetic motor configured to displace the object table, the electromagnetic motor including: a coil assembly mounted to the object table, a superconductor assembly configured to co-operate with the coil assembly to generate a driving force on the object table, and a cryogenic enclosure configured to enclose the superconductor assembly and maintain the superconductor assembly in a superconductive state; a support for supporting the electromagnetic motor; and an electromagnetic support configured to suspend the cryogenic enclosure relative to the support, thereby maintaining a gap between the cryogenic enclosure and the support.

A cryocooler mounting arrangement and magnets and cryostats including such an arrangement. The arrangement is for mounting the coldhead 21 of a cryocooler 2 in a cryostat 1 for allowing the extraction of heat from the interior of the cryostat by the cryocooler. The mounting arrangement comprises a coldhead interface portion 22a, 22b for mounting on the coldhead 21 and a sock portion 3 for mounting in the cryostat 1 and arranged for receiving the coldhead 21. The sock portion 3 comprises a receiving interface portion 32a, 32b for receiving the coldhead interface portion so as to provide thermal contact therebetween and hence to provide thermal contact between the coldhead and the interior of the cryostat. The coldhead interface portion comprises plurality of flexible finger portions 23a, 23b and the receiving interface portion comprises a bearing surface 322a, 322b against which the finger portions are arranged to rest. The mounting arrangement further comprises a clamping ring 4a, 4b for releasably clamping the finger portions 23a, 23b against the bearing surface 322a, 322b to ensure thermal contact between the coldhead interface and the receiving interface. The clamping ring 4a, 4b is held in a recess on the fingers. An outer interface portion 5 is provided at the outer vacuum wall of the cryostat 1.

A cryocooler mounting arrangement and magnets and cryostats including such an arrangement. The arrangement is for mounting the coldhead 21 of a cryocooler 2 in a cryostat 1 for allowing the extraction of heat from the interior of the cryostat by the cryocooler. The mounting arrangement comprises a coldhead interface portion 22a, 22b for mounting on the coldhead 21 and a sock portion 3 for mounting in the cryostat 1 and arranged for receiving the coldhead 21. The sock portion 3 comprises a receiving interface portion 32a, 32b for receiving the coldhead interface portion so as to provide thermal contact therebetween and hence to provide thermal contact between the coldhead and the interior of the cryostat. The coldhead interface portion comprises plurality of flexible finger portions 23a, 23b and the receiving interface portion comprises a bearing surface 322a, 322b against which the finger portions are arranged to rest. The mounting arrangement further comprises a clamping ring 4a, 4b for releasably clamping the finger portions 23a, 23b against the bearing surface 322a, 322b to ensure thermal contact between the coldhead interface and the receiving interface. The clamping ring 4a, 4b is held in a recess on the fingers. An outer interface portion 5 is provided at the outer vacuum wall of the cryostat 1.