Abstract: Sample inspection apparatus comprises a pair of magnet assemblies (28A, 28B) located in a common cryostat (10) and surrounding respective bores (24, 26) at room temperature so as to define corresponding working regions (30, 32) in the bore. A first, NMR probe (6) can be inserted in one of the bores to bring a sample into the corresponding working region, the magnetic field in that working region having a homogeneity or profile suitable for performing a NMR experiment. A second probe (5) can be inserted in the other of the bores to bring a sample into the other working region, the magnetic field in that working region having a homogeneity or profile suitable for performing a different experiment on the sample.

Abstract: Apparatus for use in a nuclear magnetic resonance system comprises a cryostat including a coolant vessel (3) containing coolant such as liquid helium (4) and a refrigerator (8) for cooling coolant in the coolant vessel, the cryostat surrounding a sample space (10). A superconducting coil (2) is located in the coolant vessel (3) for generating a Bo magnetic field in the sample space (10). Rf magnectic field generating and receiving apparatus (14)is located adjacent the sample space. A closed coolant loop (16) contains coolant such as helium which is cooled by the refrigerator (8), and a pump (20) for circulating the coolant around the loop. The coolant loop (16) is thermally coupled with the rf apparatus (14) so as to cool the rf apparatus.