• F. Marteau, C. Benabderrahmane, P. Berteaud, F. Briquez, P. Brunelle, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, J.-M. Filhol, C.A. Kitegi, O. Marcouillé, M. Massal, A. Nadji, L.S. Nadolski, R. Nagaoka, K. Tavakoli, M. Valléau, J. Vétéran
  SOLEIL, Gif-sur-Yvette
• O.V. Chubar
  BNL, Upton, Long Island, New York

SOLEIL storage ring presents a very high fraction of the total circumference dedicated to accommodate insertion devices. Over the presently planned 25 insertion devices presenting a large variety of systems, 15 have been already installed and commissioned by the end of 2008. The UV-VUV region is covered with electromagnetic devices (one HU640 and 3 HU256), offering tuneable polarisations. An electromagnet/permanent magnet undulator using copper sheets as coils for fast switching of the helicity is under construction. 13 APPLE-II types undulators, with period ranging from 80 down to 36 mm, provide photons in the 0.1-10 keV region, some of them featuring tapering or quasi-periodicity. 5 U20 in-vacuum undulators cover the 3-30 keV range whereas an in-vacuum wiggler, with magnetic forces compensation via adequate springs is designed to cover the 10^-50 keV spectral domain. R&D on cryogenic in-vacuum undulator has also been launched. A magnetic chicane using permanent magnet dipoles has also been designed in order to accommodate two canted undulators on the same straight section. The processes for optimizing the insertion devices and their achieved performances will be described.

• F. Marteau, P. Berteaud, F. Bouvet, L. Chapuis, M.-E. Couprie, J.P. Daguerre, J.-M. Filhol, A. Mary, K. Tavakoli
  SOLEIL, Gif-sur-Yvette

A new electromagnetic/permanent magnets helical undulator, with a 65 mm magnetic period is under development at SOLEIL for providing a rapid switching of the photon polarization required to perform dichroïsm experiments. The vertical field will be produced by coils fed by a fast switching power supply, with a maximum current of 350 A and a polarity switching time shorter than 100ms. The coils consist of copper sheets cut by water jet method. 26 layers of copper will be stacked together while 10 of them will be water cooled. The current-regulated power supply should be able to operate in the 4 quadrants with a 50 ppm current resolution over the full scale. The design of this home made power supply will be described. The horizontal field will be generated by NdFeB permanent magnets. The design vertical and horizontal peak field values in the helical configuration are 0.24 T at the minimum 15.5 mm gap. The magnetic design and the correction scheme will be described. A prototype was built to characterise and validate the technical choices, and the results will be discussed. The efficiency of the cooling system and the results of the magnetic measurements will be presented.