Superconducting Magnet System for the Interaction Region of SuperKEKB (7-5) -Thermal Design of the QCS-L Cryostat and Heat Load Measurements
宗 占国, 大内 徳人, 川井 正徳, 近藤 良也, 有本 靖, 山岡 広, 土屋 清澄, 王 旭東 （KEK）； 遠藤 友成, 河村 郁生 （日立プラントメカニクス）
Abstract:The QCS-L cryostat of the Superconducting (SC) magnet system for the SuperKEKB interaction region accommodates four main SC quadrupole magnets (QCS), 20 SC correction coils (16 correction coils and 4 cancel coils), and one compensation SC solenoids (ESL), with two liquid helium (LHe) vessels. The LHe vessels are suspended to a vacuum vessel by support rods and are cooled in series by one flow of sub-cooled LHe at 0.16 MPa and 4.5 K. The QCS-L cryostat fabrication was finished and was installed to its position at the accelerator beam line. The construction of its cryogenic system was completed and first commissioning was carried out by the end of 2016. This paper introduces the thermal design of the QCS-L cryostat and presents heat load measurements of the first commissioning.