Investigation of on-board hybrid pulse tube cryocooler for high temperature superconducting rotor

This paper discusses the practical realization of an advanced cooling method for superconducting rotor; on-board cryocooler. A hybrid pulse tube cryocooler was designed and tested in the rotating system. A Stirling cryocooler precooled the regenerator of the pulse tube cryocooler to produce lower temperature at the cold end of the pulse tube cryocooler. Based on adiabatic model and loss mechanism analysis, the pulse tube cryocooler was designed and fabricated. The hybrid cryocooler was aligned in the test rotor to have a concentric centerline with the rotation axis. Even if the performance of the rotating hybrid pulse tube cryocooler was not satisfactory, achieving 55 K, the feasibility of on-board cryocooler method for superconducting rotor was confirmed.