The Superferric Cyclotron Gas Stopper Magnet Design and Fabrication

• Published in: IEEE transactions on applied superconductivity Vol. 23; no. 3; p. 4101805
• Main Authors: Chouhan, S. S., Green, M. A., Bollen, G., DeKamp, J., Lawton, D., Magsig, C., Morrissey, D., Ottarson, J., Schwarz, S., Zeller, A. F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-06-2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Beams (radiation); Coils; Construction; Cyclic accelerators and storage rings; Cyclotron magnet; Cyclotrons; Design engineering; Electric connection. Cables. Wiring; Electrical engineering. Electrical power engineering; Electromagnets; Electronic tubes, masers; Electronics; Exact sciences and technology; Experimental methods and instrumentation for elementary-particle and nuclear physics; High voltages; Isotopes; Magnetic noise; Magnetic separation; Magnetic shielding; Magnetomechanical effects; natural convection helium cooling; Nuclear physics; Physics; Poles; superconducting coils; Superconducting magnets; Superconductivity; Various equipment and components; warm iron return path; Natural cooling; Compact design; Natural convection; Linear accelerator; Superconducting coils; Electrical connection; Superconducting magnet; warm iron return path; Cyclotron; High voltage; High energy; Laser spectroscopy; Cryostat; Dipole; Convection cooling; natural convection helium cooling; Facility; Cyclotron magnet; Accelerator magnets; Low-power electronics
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2013.2239350

The Facility for Rare Isotope Beams under construction and the existing National Superconducting Cyclotron Laboratory at Michigan State University will provide exotic low-energy rare isotope beams (KeV-MeV) by stopping relativistic fragments produced by projectile fragmentation at high energies ( < 50 MeV/u). The stopped radioactive ions using the cyclotron gas stopper magnet system will feed the existing program centered on precision mass measurements of exotic nuclei and laser spectroscopy. Later on, stopped radioactive ions will be available as reaccelerated low-energy beams ( < 15 MeV/u) using compact linear accelerator currently under construction. The cyclotron gas stopper magnet is a warm iron superconducting cyclotron sector dipole. The maximum field in the gap (0.18 m) is 2.75 T. The outer diameter of the magnet yoke is 4.0 m, with a pole radius of 1.1 m and \hbox{Br} = 1.8\ \hbox{T m} . The desired field shape is obtained by a pole profile. Each coil of the two halves is in a separate cryostat and connected in series through a warm electrical connection. The entire system is mounted on a high voltage platform, and will be cooled by six cryocoolers. This paper presents the magnet design and discusses various design aspects of the magnet.