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Chavanne, J.

Paper Title Page
MOPKF032 Status of the ESRF Insertion Devices 372
 
  • J. Chavanne, C. Penel, B. Plan, F. Revol
    ESRF, Grenoble
 
  The ESRF insertion devices are the object of a continuous refurbishment in order to follow the changing needs of the beamlines and increase their performances. The successful development of the narrow aperture aluminum chambers pumped by non evaporable getter has resulted in the reduction of the minimum gap from 16 mm to 11 mm . A new set of undulator magnetic assemblies with shorter magnetic periods are being prepared that make use of the lower gap. .A prototype of a new type of revolver undulator support has been completed and successfully tested. Such a structure allows the beamline user to switch between two different undulator periods in less than a minute. Three additional devices will be constructed in 2004. Three new in-vacuum undulators have been installed on the ring. One of them is based on an hybrid magnetic structure and achieves a peak field 20% higher than a pure permanent magnet undulator of identical period. Their main magnetic measurements results and interactions with the stored beam are presented.  
MOPKF034 Status of the Development of Superconducting Undulators at the ESRF 378
 
  • E.J. Wallén, J. Chavanne, P. Elleaume
    ESRF, Grenoble
 
  This note describes the present status of the development of superconducting undulators at the ESRF. Magnetic models of superconducting undulators suitable for the ESRF storage ring have been developed and evaluated. The superconducting undulators studied are horizontally polarizing undulators with a flat field profile and the vertical physical aperture of the undulator is 6 mm. Both 2D models of the local field in a period of the undulator and 3D models of the complete superconducting undulator, including the end sections and current leads, have been evaluated. The practical limit for the obtainable magnetic field has been estimated from the known performance of superconducting wire available from the cabling industry. This note also describes the conceptual design of the cryostat of the superconducting undulator and estimations of the expected heat load to the cryostat at different filling modes of the storage ring.  
WEPKF033 Application of Finite Volume Integral Approach to Computing of 3D Magnetic Fields Created by Distributed Iron-dominated Electromagnet Structures 1675
 
  • O.V. Chubar, C. Benabderrahmane, O. Marcouillé, F. Marteau
    SOLEIL, Gif-sur-Yvette
  • J. Chavanne, P. Elleaume
    ESRF, Grenoble
 
  Iron-dominated electromagnet structures are traditionally considered as a domain of applications of the Finite-Element Method (FEM). FEM computer codes provide high accuracy for "close circuit" type geometries, however they are much less efficient for distributed geometries consisting of many spatially separated magnets interacting with each other. Examples of such geometries related to particle accelerators are insertion devices, quadrupole and sextupole magnets located close to each other, magnets with combined functions. Application of the finite volume integral approach implemented in the Radia 3D magnetostatics code to solving such geometries is described. In this approach, space around individual magnets does not require any meshing. An adaptive segmentation of iron parts, with the segmenting planes being roughly perpendicular or parallel to the expected directions of magnetic flux lines, minimizes dramatically the necessary CPU and memory resources. If a geometry is, nevertheless, too big for its complete interaction matrix to fit into memory, a special scheme of relaxation "by parts" can be applied. The results of calculations made for the SOLEIL electromagnet undulator HU256 will be presented.