Conventional Magnets/Light Sources

Paper Title Page
MPPT066 Pulsed Undulator for Polarized Positron Production 3676
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We represent here elements of design and results of testing for helical undulator with ~2.5-mm period, manufactured in Cornell LEPP for polarized positron production at SLAC. At 2.3 kA undulator reaches K~0.2 and operated up 30 Hz.  
MPPT075 Analysis and Design of Backing Beam for Multipole Wiggler (MPW14) at PLS 3940
  • H.-G. Lee, C.W. Chung, H.S. Han, Y.G. Jung, D.E. Kim, W.W. Lee, K.-H. Park, H.S. Suh
    PAL, Pohang, Kyungbuk
  Pohang Accelerator Laboratory (PAL) had developed and installed a Multipole Wiggler (MPW14) to utilize high energy synchrotron radiation at Pohang Light Source (PLS). The MPW14 is a hybrid type device with period of 14 cm, minimum gap of 14 mm, maximum flux density of 2.02 Tesla and total magnetic structure length of 2056 mm. The support locations and structure of an insertion device are optimized to achieve a minimum deflection due to the magnetic loads. A Finite Element Analysis (FEA) is performed to find out the amount of maximum deflection and optimal support positions on the backing beam, the support and drive structures of the MPW14 under expected magnetic load of 14 tons. To reduce the deflection effect further, two springs are designed and installed to compensate the gap dependent magnetic loads. The optimized deflection is estimated to be about 20.6 ? while the deflection before optimization is 238 ?.  
MPPT076 Conceptual Designs of Magnet Systems for the Taiwan Photon Source 3979
  • C.-H. Chang, H.-H. Chen, T.-C. Fan, M.-H. Huang, C.-S. Hwang, J.C. Jan, W.P. Li, F.-Y. Lin, H.-C. Su
    NSRRC, Hsinchu
  The National Synchrotron Radiation Research Center (NSRRC) at Taiwan is designing a 3.0 GeV energy with ultra-low emittance storage ring for new Taiwan Photon Source (TPS) project. The storage has a circumference of 514 m with 24 periods of double-bend achromatic magnet system. The conceptual designs for each magnet family for the storage ring are optimize for operation of electron energy at 3.0- 3.3 GeV. This paper reviews the preliminary design and the key accelerator magnet issues.  
MPPT079 Commissioning of an APPLE-II Undulator at Daresbury Laboratory for the SRS 4051
  • J.A. Clarke, F.E. Hannon, D.J. Scott, B.J.A. Shepherd, N.G. Wyles
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  A new variable polarisation undulator of the APPLE-II type has been designed and constructed at Daresbury Laboratory. Initial magnet testing of the 56mm period device was followed by an intensive period of shimming to improve the field quality. After this was successfully completed the undulator was installed into the SRS and tests made of the effect of the device upon the electron beam. This beam commissioning was completed in a very short space of time with the beamline being given full control of the gap and phase of the magnet within a few weeks of installation. This paper summarises the measurement of the magnet and the shimming techniques employed to improve the field quality. It also describes the effect of the device upon the stored 2 GeV electron beam and the measures taken to minimise these effects during user operations.  
MPPT080 Design, Fabrication and Characterization of a Large-Aperture Quadrupole Magnet for CESR-c 4063
  • M.A. Palmer, J.A. Crittenden, J. Kandaswamy, A. Temnykh
    Cornell University, Department of Physics, Ithaca, New York
  • T.I. O'Connell
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  Funding: National Science Foundation.

Installation of a radiative Bhabha luminosity monitor for CESR-c operation in 2004 required replacing a 40-mm aperture steel quadrupole magnet with one of aperture 75 mm, while maintaining field-quality tolerances at the level of a few parts in $104. We present the design methodology using 2D- and 3D-finite-element field calculations, compare the calculated 3D integrals to flip-coil measurements, and discuss related mechanical tolerances.

MPPT081 Undulator for the LCLS Project - Changes in the Magnet Structure Design 4075
  • E. Trakhtenberg, J. Erdmann, B. Powers
    ANL, Argonne, Illinois
  The design modifications of a new hybrid-type undulator with a fixed gap of 6.4 mm, a period of 30 mm and a length of 3.4 m are presented. The prior pole design included side "wings" which were used for precise positioning, and clamps to fasten poles to the magnet base. This design has been replaced by a more straightforward assembly, where the pole is attached to the magnet structure base using only two screws. Tests were performed on the vanadium permendure pole material to prove that the threaded holes are easy to fabricate and are able to successfully withstand the torque required to hold the pole in place. A fixture was also developed to ensure the precise location of the poles on the base during assembly. In addition to the pole modifications, the magnet structure base is now manufactured as one piece as opposed to three, which greatly eases assembly. Finally, a small section of the original prototype had these changes successfully implemented, and the test results are presented.  
MPPT082 The 8 cm Period Electromagnetic Wiggler Magnet with Coils Made from Sheet Copper 4093
  • G.H. Biallas, S.V. Benson, T. Hiatt, G. Neil, M.D. Snyder
    Jefferson Lab, Newport News, Virginia
  Funding: Work supported by the US DOE Contract #DE-AC05-84ER40150, the Office of Naval Research, the Air Force Research Laboratory, the U.S. Army Night Vision Laboratory and the Commonwealth of Virginia.

An electromagnetic wiggler, now lasing at the Jefferson Lab FEL, has 29 eight cm periods with K variable from 0.6 to1.1 and gap of 2.6 cm. The wiggler was made inexpensively in 11 weeks by an industrial machine shop. The conduction cooled coil design uses copper sheet material cut to forms using water jet cutting. The conductor is cut to serpentine shapes and the cooling plates are cut to ladder shape. The sheets are assembled in stacks insulated with polymer film, also cut with water jet. The coil design extends the serpentine conductor design of the Duke OK4 to more and smaller conductors. The wiggler features graded fields in the two poles at each end and trim coils on these poles to eliminate field errors caused by saturation. An added critical feature is mirror plates at the ends with integral trim coils to eliminate three dimensional end field effects and align the entrance and exit orbit with the axis of the wiggler. Details of construction, measurement methods and excellent wiggler performance are presented.

MPPT083 Radiation Damage to Advanced Photon Source Undulators 4126
  • S. Sasaki, C. Doose, E.R. Moog, M. Petra, I. Vasserman
    ANL, Argonne, Illinois
  • N.V. Mokhov
    Fermilab, Batavia, Illinois
  Funding: Supported by the U.S. DOE Office of Science under Contract No. W-31-109-ENG-38.

Radiation-induced magnetic field strength losses are seen in undulator permanent magnets in the two sectors with small-aperture (5 mm) vacuum chambers. Initially, simple retuning of the affected undulators could restore them to full operation. As the damage has accumulated, however, it has become necessary to disassemble the magnetic arrays and either replace magnet blocks or remagnetize and reinstall magnet blocks. Some of the damaged magnet blocks have been studied, and the demagnetization was found to be confined to a limited volume at the surface close to the electron beam. Models for the magnetic damage were calculated using RADIA* and were adjusted to reproduce the measurements. Results suggest that a small volume at the surface has acquired a weak magnetization in the opposite direction. Small magnet samples provided by NEOMAX and Shin-Etsu are being placed in the storage ring tunnel for irradiation exposure testing. Simulations of the radiation environment at the undulators have been performed.

*O. Chubar, P. Elleaume, J. Chavanne, J. Synchrotron Radiat. 5, 481 (1998).

MPPT084 Dipole and Quadrupole Magnets for the Duke FEL Booster Injector 4147
  • S. Mikhailov
    DU/FEL, Durham, North Carolina
  • N. Gavrilov, D.G. Gurov, O.B. Kiselev, A.B. Ogurtsov, E.R. Rouvinsky, K.Zh. Zhiliaev
    BINP SB RAS, Novosibirsk
  Funding: This work is supported by U.S. DOE grant # DE-FG02-01ER41175 and by AFOSR MFEL grant # F49620-001-0370.

The full energy booster injector for the Duke FEL storage ring is presently under installation. The booster is designed to provide continuous injection into the Duke FEL storage ring in the top-off mode at the energy variable from 270 MeV to 1.2 GeV. The magnetic elements for the booster have been fabricated and magnetically measured in the Budker Institute of Nuclear Physics, Russia. The paper presents magnetic and mechanical design of the booster dipole and quadrupole magnets and results of their magnetic measurements. Results of simulation of the booster lattice taking into account residual field and non-linearity of the magnets are also presented.

MPPT085 Fast Magnets for the NSLS-II Injection 4165
  • I.P. Pinayev, T.V. Shaftan
    BNL, Upton, Long Island, New York
  Funding: Under Contract with the U.S. Department of Energy Contract Number DE-AC02-98CH10886.

Third generation light sources require top-off operation in order to provide proper stability of the photon beam. In this paper we present the conceptual design of the fast pulsed magnets used for injection into the 3 GeV storage ring.

MPPT086 Conventional Magnets Design for the Candle Storage Ring 4182
  • V.G. Khachatryan, A. Petrosyan
    CANDLE, Yerevan
  The lattice of 216m long CANDLE storage ring (16 Double Bend Achromat cells) will contain 32 gradient dipole magnets, 80 quadrupole magnets of three types and two types of 64 sextupole magnets. Magnetic as well as mechanical design of those magnets has been performed relying on extensive world experience. Computer simulations and large volume of computations have been carried out to design magnets that conform to strict requirements.  
MPPT090 Design, Construction and Field Characterization of a Variable Polarization Undulator for SOLEIL 4242
  • B. Diviacco, R. Bracco, C. Knapic, D. Millo, D.Z. Zangrando
    ELETTRA, Basovizza, Trieste
  • O.V. Chubar, A. Dael, M. Massal
    SOLEIL, Gif-sur-Yvette
  • Z. Martí
    LLS, Bellaterra (Cerdanyola del Vallès)
  Two variable polarization undulators (HU80) are being designed and constructed in the framework of an ELETTRA-SOLEIL collaboration. The four-quadrant permanent magnet structure, of the APPLE-II type, will produce various polarization modes by means of parallel or anti-parallel displacement of two diagonally opposite magnet arrays. In this paper the main aspects of the magnetic and mechanical design will be summarized. The post-assembly field quality optimization methods will be described in some detail, discussing our approach to the correction of phase, trajectory and multipole errors. Finally the magnetic measurement results on the completed device will be presented.  
MPPT091 Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies 4260
  • J.G. Hubrig
    Innovation Services, Inc, Knoxville, Tennessee
  • G.H. Biallas
    Jefferson Lab, Newport News, Virginia
  Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in processing parameters accounts for their continued popularity in engineering applications, but also for the tendency to overlook or misinterpret the requisite processing parameters on the manufacturing floor. Resin system impregnation must be managed in detail in order to achieve device life cycle reliability. This closer look reveals how manufacturing floor level management of material acceptance, handling and storage, pre- and post- impregnation processing and cure can be built into a manufacturing plan to increase manufacturing yield, lower unit cost and ensure optimum life cycle performance of the coil.