The first cool-down test of the 6 meter-long-cryomodules for superconducting rf test facility (STF) at KEK

KEK has been constructing the STF as the center of the ILC-R&D in Asia from 2005. In this construction, KEK developed two 6-m cryomodules in order to get manufacturing and operational experiences of the superconducting RF cavity and cryomodule toward the ILC. Two cryomodules were designed to accommodate 4 nine-cell cavities in each cryostat. At the first step, the cryomodules with one cavity were assembled and their cold tests were performed. And in the following test, the cryomodule with four cavities was reassembled and the cold test of this module is being carried out now. In this paper, we will report the design of the cryomodules briefly and the thermal results of the cold tests.