Installation and commissioning of a cryogen distribution system for the TPS project

• We overcame the space constraint to install the multichannel transfer line.
• The proposed method and technique of heat load measurement was feasible and successful.
• The average heat loads of loops A and B were 44.57 W and 42.47 W, respectively, after subtracting the qTD, qTD-H, qMD-TL and 5.68% flash loss.
• The results show also that the test could be duplicated within 6% deviation for varied transfer rates from the main dewar.
• TAO phenomena were observed, and a suppression method was proposed.

A cryogen distribution system was installed and commissioned to transfer liquid nitrogen (LN2) and liquid helium (LHe) from storage dewars to superconducting radio-frequency (SRF) cavities for the 3-GeV Taiwan Photon Source (TPS) project. The cryogen distribution system comprises one distribution valve box (DVB), four control valve boxes (CVB) and seven sections of multichannel transfer line (MCL). The DVB distributes the LHe and LN2 to the CVB, and then to the SRF cavities through independent vacuum-jacketed transfer lines. The vaporized GHe and GN2 from the cryomodules are collected via the MCL. The cryogen distribution system was installed and commissioned from October 2014 to the end of March 2015. This paper presents the installation, pre-commissioning and commissioning of the cryogen distribution system, and describes the heat load test. Thermal acoustic oscillation (TAO) was found in the GHe process line; this phenomenon and its solution are also presented and discussed.