• G. Lebec, J. Chavanne
  ESRF, Grenoble
• C. Benabderrahmane
  SOLEIL, Gif-sur-Yvette

Cryogenic Permanent Magnet Undulators (CPMU) are currently being developed in some Synchrotron Light Sources. Low Temperature NdFeB Permanent Magnets are used to achieve both a high remanence and a high coercive field. Low temperature magnetization hysteresis curves cannot be obtained by a simple transformation of ambient temperature curves; this requires a specific simulation tool. A Monte-Carlo based Permanent Magnet Simulator has been developed at the ESRF. In this simulator, the magnets can be described as a set of several magnetic grains. The model inputs are physical parameters such as anisotropy constants, easy-axis distribution and coercive field. The orientation of magnetic moments are calculated for each grain according to an analytical model and optimization methods are used for fast computations. Magnetization versus external field curves is calculated in a few seconds. This fits with low temperature NdFeB magnetization measurements. These curves have been efficiently used to obtain Radia material parameters for CPMU design.

• 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.