Open AccessLong term operation of the superconducting triplet quadrupoles with cryocoolers
Author(s) -
K. Kusaka
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1559/1/012071
Subject(s) - cryocooler , cryostat , superconducting magnet , nuclear engineering , quadrupole magnet , refrigeration , liquid helium , cryogenics , magnet , superconductivity , materials science , nuclear physics , physics , helium , mechanical engineering , engineering , atomic physics , thermodynamics , condensed matter physics
Superconducting triplet quadrupoles (STQs) with cryocoolers characterize the BigRIPS in-flight separator and radioactive isotope (RI) beam delivery lines in the RIKEN RIBF (Radioactive Isotope Beam Factory) project. The STQ magnet is a large-aperture superferric quadrupole triplet cooled by liquid helium bath cooling method in a single cryostat. The STQ cryostat is designed to be operated continuously with a Gifford-McMahon (GM)/Joule-Thomson (JT) cryocooler and a GM cryocooler. We operate 22 STQ systems for more than twelve years without warm-up the magnets. We report operational experiences, such as degradation of cooling capacity and failures of compressors, in the long-term operation of the STQ systems. Replacement of ageing cryocooler unit is discussed to improve the cooling capacity.