Abstract: In Nuclear Magnetic Resonance (NMR) spectroscopy and microscopy, noise from the receiver coil of the probe limits sensitivity. This noise may be reduced by cooling the receiver coil. Noise may be even further reduced by use of a superconducting receiver coil. However, high temperature superconductors must be maintained at temperatures significantly below the critical temperature, typically in the range of 10-60 K for proper performance. The invention provides an apparatus for cooling an NMR receiver coil to a desired temperature using a closed circuit refrigeration system. A cold fluid is circulated to a heat exchanger which is in thermal contact with a thermally conductive substrate having low magnetic susceptibility. The receiver coil is deposited on a portion of the substrate located distally from the heat exchanger. In the preferred embodiment, the substrate is sapphire and the receiver coil is a superconductive oxide.