The use of high-temperature superconducting (HTS) coils (those that superconduct when cooled to temperature of about 90 Kelvin) in certain high-energy physics devices would greatly reduce the difficulty and operating costs of using those devices. But, minimizing heat leakage from the room temperature, electrical power supply leads into the cryogenic system remains a significant problem. There is a need to improve cooling efficiency in high-energy physics particle detectors, such as that used in the MINOS experiment. The goal of this two-phase project is to develop and demonstrate an HTS power supply device called a "flux pump" that enhances the current supplied to the coil; this in turn reduces the requirement for current through the room-temperature current leads and thus reduces heat leakage from those leads. In Phase I of the project, the flux pump will be designed, a working scale model will be built, and performance will be evaluated. Phase II will include design fabrication, and operation of an HTS coil assembly and a scaled-up flux pump, together with all cryogenic system components and controls.Commercial Applications and other Benefits as described by the awardee:Successful development of the HTS flux pump will significantly improve the energy efficiency and commercial applicability of HTS technology. Reduction of heat leakage means that currently available cryocoolers can be used to provide refrigeration, thus avoiding the need for expensive transport and storage of liquid cryogens. Commercial businesses that would benefit include HTS conductor manufacturers, HTS magnet developers, and producers of cryogenic equipment.