Research and development that attempts to reduce the weight of railroad vehicle and improve efficiency is being advanced by applying high-temperature superconducting wire material to the winding of 4 MVA-class traction transformer. To compose a cooling system that absorbs the generation of heat due to AC loss, a refrigerator that has the refrigerating capacity corresponds to the calorific value becomes indispensable. In this report, we described the results from the development stage of a 65 K,1 kW-class active-buffer, pulse-tube refrigerator.
