• T. Hiatt, K.S. Baggett, J.M. Beck, J.G. Dail, L. Harwood, J. Meyers, M. Wiseman
  JLAB, Newport News, Virginia

Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) currently has maximum beam energy of 6 GeV. The 12 GeV Upgrade Project will double the existing energy and is currently scheduled for completion in 2014. This doubling of energy requires modifications to the beam transport system which includes the addition of several new magnet designs and modifications to many existing designs. Prototyping efforts have been concluded for two different designs of quadrupole magnets required for the upgrade. The design, fabrication and measurement will be discussed.

Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.

• E.S. Fischer, A. Bleile, E. Floch, J. Macavei, A. Mierau, P. Schnizer, C. Schroeder, A. Stafiniak, F. Walter
  GSI, Darmstadt
• W. Gaertner, G. Sikler
  BNG, Würzburg

The 100 Tm synchrotron SIS 100 is the core component of the international Facility of Antiproton and Ion Research (FAIR) to be built in Darmstadt. An intensive R&D period was conducted to design 3m long 2T dipoles providing a stable ramp rate of 4 T/s within an usable aperture of 115mm x 60mm with minimum AC losses, high field quality and good long term operation stability. Three full size dipole - and one quadrupole magnets were built. Recently the first dipole magnet, produced by Babcock Noell, was intensively tested at the GSI cryogenic test facility. We present the measured characteristic parameters: training behaviour, the field quality along the load line for DC operation as well as on the ramp, AC losses, and the cryogenic operation limits. We compare them to the calculated results as well as to the requested design performance. Based on the obtained results we discuss adjustments for the final design.

• S.A. Kahn, R.P. Johnson, M. Turenne
  Muons, Inc, Batavia
• F. Hunte, J. Schwartz
  NHMFL, Tallahassee, Florida

High temperature superconductors (HTS) have been shown to carry significant current density in the presence of extremely high magnetic fields when operated at low temperature. The successful design of magnets needed for high energy physics applications using such high field superconductor depends critically on the detailed wire or conductor parameters which are still under development and not yet well-defined. The HTS is being developed for accelerator use by concentrating on the design of solenoid magnet that will have a useful role in cooling muon beam phase space. A conceptual design of a high field solenoid using YBCO conductor is being analyzed. Mechanical properties of the HTS conductors will be measured along with engineering current densities (JE) as a function of temperature and strain to extend the HTS specifications to conditions needed for low temperature applications. HTS quench properties are proposed to be measured and quench protection schemes developed for the solenoid magnet.

• S. Boucher, R.B. Agustsson, P. Frigola, A.Y. Murokh, M. Ruelas
  RadiaBeam, Marina del Rey
• F.H. O'Shea, J.B. Rosenzweig, G. Travish
  UCLA, Los Angeles, California

The fixed-field alternating-gradient (FFAG) betatron has emerged as a viable alternative to RF linacs as a source of high-energy radiation for industrial and security applications. RadiaBeam Technologies is currently developing an FFAG betatron with a novel induction core made with modern low-loss magnetic materials. The principle challenge in the project has been the design of the magnets. In this paper, we present the current status of the project, including results of the magnet design and testing.

• D. Neuvéglise
  SIGMAPHI S.A., Vannes
• F. Méot
  CEA, Gif-sur-Yvette

Funding: ANR contract nb : NT05-1₄1853

This paper presents an alternative design of the magnet for the RACCAM project. The aim of this collaboration is to study and build a prototype of a scaling spiral FFAG as a possible medical machine for hadron therapy. The magnet was first designed with a variable gap to produce the desired field law B=B₀(r/r₀)^k. The key feature in the “scaling” behavior of the magnet is in getting the fringe field extent to be proportional to the radius. Although the fringe field is increasing with gap dimension, we have obtained quit constant tunes in both horizontal and vertical by using a variable chamfer. An alternative magnet design was then proposed with parallel gap and distributed conductors on the pole to create the required field variation. This solution requires about 40 conductors along the pole and much more power than the gap shaping solution. We expect a much better tune constancy even without variable chamfer. We can think about an “hybrid” magnet with parallel gap at small radii and gap shaping afterward. Such a solution could take advantages of both solutions.