Many modern superconducting magnets, such as those used in advanced particle accelerators, small scale fusion reactors, medical systems and basic magnetic research are cooled to their low operating temperature by contact with a refrigerator. It is frequently a challenge for designers to cool these large magnets uniformly due to thermal gradients that occur at cryogenic temperature. Systems experience localized heating due to radiation from a particle beam, hysteresis loss in superconducting coils, and from eddy currents induced by changing magnetic fields. This heat causes hot spots that limit magnet performance. Higher thermal conductivity materials are needed for advanced magnets and cryogenic systems. A recent version of heat pipe technology, first introduced in the 1990s and called the pulsating heat pipe (PHP), received enormous attention using room temperature fluids for near-room temperature applications. Since 2010, the same devices have also been explored in the cryogenic regime. In both regions PHPs have been shown to be an extremely effective heat transfer device. This SBIR investigates the use of pulsating heat pipes for use in modern superconducting magnet systems. Performance of various PHP configurations at low temperature will be measured and characterized with an ultimate goal of significantly improving thermal performance of a large conduction-cooled superconducting magnets. Resulting commercial applications will range from magnets used in particle accelerators to medical applications such as MRI and proton therapy cancer treatment.
