A cooling system for use in a superconducting magnet comprising a high temperature superconductor, HTS, coil. The cooling system comprises a refrigeration unit, one or more coolant channels, and a pumping unit. The refrigeration unit is configured to cool a gas, wherein the gas is hydrogen or helium. The one or more coolant channels are configured to be placed in thermal contact with components of the superconducting magnet and to carry said gas. The pumping unit is configured to pump said gas through the coolant channels. The refrigeration unit and pumping unit are configured to maintain the gas at a pressure and temperature such that a Joule-Thompson coefficient of the gas is positive, and the coolant channel is configured to reduce the pressure of gas as it flows through the channel by one or more of a throttle, a valve, and choice and/or variance of a cross section of the coolant channel.