In this paper, a full localization 250W@4.5K helium cryogenic refrigerator was commissioning up to nearly 470 hours. A step-by-step commissioning strategy about the stability of high and low pressure of refrigerator, cool-down processes in cold box and cooling capacity evaluation of refrigerator was carried out. Dynamic characteristics including the adjustment of pneumatic valves for the stability of high and low pressure, 300~4.5K temperature evolution of heat exchangers and turbine expanders in the cold box and cooling capacity fluctuation are experimentally discussed. The results are helpful to more precisely understand and commissioning hundred watts level helium cryogenic refrigerator.
Keywords dynamic characteristics, commissioning strategy, cool-down process, full localization, helium cryogenic refrigerator