Pascal Elleaume

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RADIA is a three-dimensional magnetostatics computer code optimized for the design of undulators and wigglers. It solves boundary magnetostatics problems with magnetized and current-carrying volumes using the boundary integral approach. The magnetized volumes can be arbitrary polyhedrons with non-linear (iron) or linear anisotropic (permanent magnet)(More)
A very simple pinhole camera set-up has been built to diagnose the electron beam emittance of the ESRF. The pinhole is placed in the air next to an Al window. An image is obtained with a CCD camera imaging a fluorescent screen. The emittance is deduced from the size of the image. The relationship between the measured beam size and the electron beam(More)
A new class of undulator capable of producing linear and/or helical polarization is described. The magnetic field, power, spectral flux, brilliance and interactions with the electron beam of such undulators are discussed. The case of Helios, an undulator presently installed on the ESRF, is discussed in detail.
The European Synchrotron Radiation facility is presently operating 47 segments of insertion devices (IDs). A record brilliance of 1 x 10(20) photons s(-1) (0.1% bandwidth)(-1) mm(-2) mrad(-2) has been reached. Almost all devices are built with permanent magnets with or without iron pole pieces. They have been mechanically and magnetically designed and(More)
Lowering the temperature of NdFeB materials increases their field remanence and intrinsic coercivity. This property is potentially interesting for the construction of a cryogenic permanent in-vacuum undulator (CPMU). Around 150K, the coercivity is so increased that the NdFeB material is comparable to the Sm2Co17 material as far as resistance to radiation(More)
Before the commissioning of SPring-8, the in-vacuum hybrid undulator developed at SPring-8 had been brought to the ESRF for the first beam test in the summer of 1996. The purpose of this test was to investigate the influence of the in-vacuum undulator on the beam and check its vacuum system. However, heating by the resistive wall impedance turned out to be(More)
The first experimental applications of the undulator gap-scan technique in X-ray absorption spectroscopy are reported. The key advantage of this method is that during EXAFS scans the undulator is permanently tuned to the maximum of its emission peak in order to maximize the photon statistics. In X-MCD or spin-polarized EXAFS studies with a helical undulator(More)
The field integral tolerances required on third generation synchrotron sources are of the order of 10-20 Gcm in the whole gap range of an insertion device. This can be achieved without electromagnet correction by a proper magnetic design of the field termination. The paper describes several such end field terminations to be used for planar undulators. A new(More)