Failure analysis for cryogenic system operation at NSRRC

Two 450 W cryogenic systems were installed on the year 2002 and 2006, respectively at NSRRC. So far, one 450 W cryogenic system is cooling three superconducting magnets and one superconducting cavity. The new system will serve for five superconducting magnets on the year 2007. This paper presents the abnormal operation for the system, which induces the fluctuations for pressure, temperature, and flow rate, respectively. Solutions for these failures are shown and discussed.