Magnets

Conventional Magnets/Switchyards

Paper Title Page
MPPT014 Design Concept for AGS Injection Kicker Upgrade to 2 GeV 1380
 
  • G.D. Wait, R.B. Armenta, M.J. Barnes, E.W. Blackmore, O. Hadary
    TRIUMF, Vancouver
  • L. Ahrens, C.J. Gardner, W. Zhang
    BNL, Upton, Long Island, New York
 
  Funding: Canada Foundation for Innovation, U.S. Dept of Energy.

The present AGS injection kickers at A5 location were designed for 1.5 GeV proton injection. Recent high intensity runs have pushed the transfer kinetic energy to 1.94 GeV, but with an imperfect matching in transverse phase space. Space charge forces result in both fast and slow beam size growth and beam loss as the size exceeds the AGS aperture. A proposed increase in the AGS injection energy to 2 GeV with adequate kick strength would greatly reduce the beam losses making it possible to increase the intensity from 70 TP (70 * 1012 protons/s) to 100 TP. R&D studies are being undertaken by TRIUMF, in collaboration with BNL, to design two new kicker magnets for the AGS A10 location to provide an additional kick of 1.5 mrad to 2 GeV protons. TRIUMF has proposed a design for a 12.5 W transmission line kicker magnet with rise and fall times of 100 ns, 3% to 97% and field uniformity of ±3% over 90% of the aperture, powered by matched 12.5 W pulse-forming lines. This paper describes the present status of a prototype design including the results of detailed 2D and 3D electromagnetic modeling of a transmission line kicker magnet and PSpice time domain analysis of the magnetic kick strength.

 
MPPT016 Beam Injection for the PF-AR with a Single Pulsed Quadrupole Magnet 1517
 
  • K. Harada, Y. Kobayashi, T. Mitsuhashi, T. Miyajima, S. Nagahashi, T. Obina, A. Ueda
    KEK, Ibaraki
 
  We develop the injection system for PF-AR (Photon Factory Advanced Ring for Pulsed X-ray) with single pulse quadrupole (PQ) magnet without pulse local bump of the stored beam with four dipole kickers. The pulse quadrupole magnet has the length of 30cm, the field gradient of 3T/m, half-sine-form pulse width of 2.4mSec, measured inductance of 1.8mH and the peak current of about 2000A. With this magnet, the amplitude of the injected beam can be reduced to about the half of that only with septum magnets and the reduced amplitude is almost the same as the case of the usual injection with the pulse bump of the stored beam. We installed PQ-magnet at the short straight section near the south symmetric point of PF-AR in this summer of 2004 and succeeded to inject beam to the storage ring during the machine study in autumn, 2004.  
MPPT017 Design of Switching Magnet for 20-MeV Beamlines at PEFP 1575
 
  • H.S. Suh, H.S. Han, S.-H. Jeong, Y.G. Jung, H.-S. Kang, H.-G. Lee, K.-H. Park, C. K. Ryu
    PAL, Pohang, Kyungbuk
 
  Funding: Ministry of Science and Technology.

The PEFP(Proton Engineering Frontier Project) proton linac is designed to have two proton beam extraction lines at the 20-MeV and 100-MeV end. The 20-MeV extraction line is branched out into 5 beamlines by using the switching magnet. The magnet bends the proton beam by +20, +10, 0, -10, -20 degrees, respectively, and has an AC frequency of 5 Hz with a programmable ac power supply. It employs an H-shape, 0.45 T magnetic field, 0.5 m effective magnet length, 30x5 cm bore aperture. The pole shape is optimized for the field levels. Laminated steel of 0.5 mm is enough to suppress the eddy current effect in the yoke. This paper presents the magnet specification and primary design.

 
MPPT019 Magnet Design for the ISIS Second Target Station Proton Beam Line 1652
 
  • C.M. Thomas, D.C. Faircloth, S.J.S. Jago
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
 
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, is an intense source of neutrons and muons for condensed matter research. The accelerator facility delivers an 800 MeV proton beam of 2.5x1013 protons per pulse at 50 Hz to the present target station. As part of a facility upgrade, it is planned to share the source with a second, 10 Hz, target station. The beam line supplying this target will extract from the existing target station beam line. Electromagnetic Finite Element Modelling techniques have been used to design the magnets required to meet the specified beam line optics. Kicker, septum, dipole, quadrupole, and steering magnets are covered. The magnet design process, involving 2D and 3D modelling, the calculation of ideal shims and chamfers, choice of steel, design of conducting coils, handling of heating issues and eddy current effects, is discussed.  
MPPT067 Stray Field Reduction in ALS Eddy Current Septum Magnets 3718
 
  • D. Shuman, W. Barry, S. Prestemon, R.D. Schlueter, C. Steier, G.D. Stover
    LBNL, Berkeley, California
 
  Funding: This work was supported by the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

Stray field from an eddy current septum magnet adversely affects the circulating beam and can be reduced using several techniques. The stray field time history typically has a fast rise section followed by a long exponential decay section when pulsed with a half sine drive current. Changing the drive current pulse to a full sine has the effect of both reducing peak stray field magnitude by ~3x, and producing a quick decay from this peak to a lower field level which then has a similar long decay time constant as that from the half sine only drive current pulse. A method for tuning the second half sine (reverse) drive current pulse to eliminate the long exponential decay section is given.