| Paper |
Title |
Page |
| WEPC048 |
Experimental Characterization of the Insertion Device Effects on Beam Dynamics at SOLEIL
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2097 |
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- P. Brunelle, C. Benabderrahmane, F. Briquez, O. V. Chubar, O. Marcouillé, F. Marteau, A. Nadji, L. S. Nadolski
SOLEIL, Gif-sur-Yvette
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SOLEIL, the French 2.75 GeV third generation light source, has been delivering photons to beam lines in routine operation since January 2007. The storage ring is presently equipped with eleven insertion devices: 3 in-vacuum 20mm period undulators (U20), 1 Apple-II type 52mm period undulator (HU52), 3 Apple-II type 80mm period undulators (HU80), 3 electromagnetic 256mm period undulators (HU256) and 1 electromagnetic 640mm period 10m long undulator (HU640). Commissioning of insertion devices consists of characterizing all the effects on beam dynamics in terms of focussing, injection efficiency, beam lifetime and sensitivity to working point, and also in optimizing feedforward tables in order to compensate for closed orbit distortions during field variations (this last point is detailed in other papers). We will focus here on the significant effects observed with some undulators. Measurements, using electron beam, of the transverse variation of field integrals, were helpful to understand bad effects impacting the daily operation. The introduction of real magnetic characteristics in the lattice model is in progress in order to further optimize the working point.
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| WEPC102 |
Commissioning of the Electromagnetic Insertion Devices at SOLEIL
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2237 |
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- F. Briquez, P. Brunelle, O. V. Chubar, M.-E. Couprie, J.-M. Filhol, O. Marcouillé, F. Marteau, A. Nadji, L. S. Nadolski, M. Valleau, J. Vétéran
SOLEIL, Gif-sur-Yvette
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SOLEIL is the French 2.75 GeV third generation synchrotron radiation light source. Eleven undulators are installed yet in the storage ring and nineteen more Insertion Devices (ID) will be installed on the ring by January 2010. Among the installed IDs, there are four electromagnetic undulators of two different designs: one 640 mm period air coils undulator called HU640 and three 256 mm period undulators called HU256, made up of independent H yoke dipoles. The HU640 provides photons in any polarisation from linear to elliptical, in a range extending from 5 to 40 eV, thanks to three different groups of coils powered independently. The HU256, which are subject to hysteresis, provide horizontal and vertical, periodic or quasi-periodic linear polarisations, and also circular polarisation, covering a total range from 10 eV to 1 keV. The effects of each undulator on the closed orbit have been extensive studied, and compensated, using dedicated embedded steering coils. The correction method will be explained and its results will be shown and compared to the magnetic measurements. Finally, the first measurements of the radiation produced will be shown and compared to previsions.
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| WEPC107 |
Observation and Interpretation of Dynamic Focusing Effects Introduced by APPLE-II Undulators on Electron Beam at SOLEIL
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2249 |
| |
- O. V. Chubar, P. Brunelle, M.-E. Couprie, J.-M. Filhol, A. Nadji, L. S. Nadolski
SOLEIL, Gif-sur-Yvette
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The paper presents the results of electron beam closed orbit distortion (COD) and tune shift measurements performed on three different APPLE-II type undulators when making horizontal displacements of the electron beam orbit in those straight sections of the SOLEIL storage ring where these undulators are installed. In agreement with data from other storage rings, our results show that, when APPLE-II undulators are used in elliptical, linear-vertical or linear-tilted polarization modes, the measured tune shifts and the COD can not be explained only by residual first-order focusing effects: taking into account the second-order, or dynamic focusing effects, is necessary. We describe a COD interpretation method allowing for straightforward comparison of the measured effects on electron beam with the corresponding predictions from calculations and magnetic measurements. The observed dynamic effects are in good agreement with calculations performed using RADIA code. We also discuss possible modification of the figures of merit to be used at computer-aided shimming of APPLE-II undulators, which would allow for simultaneous minimization of the first- and second-order focusing effects.
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| WEPC016 |
Operation Status and Performances Upgrade on SOLEIL Storage Ring
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2022 |
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- J.-M. Filhol, J. C. Besson, F. Bouvet, P. Brunelle, L. Cassinari, M.-E. Couprie, J.-C. Denard, C. Herbeaux, J.-F. Lamarre, J.-P. Lavieville, P. Lebasque, M.-P. Level, A. Loulergue, P. Marchand, A. Nadji, L. S. Nadolski, R. Nagaoka, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette
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SOLEIL is the French 2.75 GeV third generation synchrotron light source delivering beam to users since January 2007. Beginning of 2008 up to 13 beam-lines are taking beam, 7 from insertion devices (IDs), 2 from IR ports, and 4 from dipole ports, and 6 of them are open to external Users. Users have a full control of their IDs. With a 300 mA stored beam current in multi-bunch filling pattern, and position stability in the few micron range, the main target performances have been reached. A beam of 50 mA in 8 bunches was delivered to users for the first time in December 2007 for time structure experiments. Operation and performance status will first be given, namely subsystem behaviour (RF, vacuum, …), beam optics, orbit stability, beam lifetime, and operation statistics. Then the main objectives for 2008 will be reviewed: delivery of 4000 hours of user beam time, installation and commissioning of a second cryomodule for reaching the 500 mA current target, construction and installation of 6 new IDs leading to a total number of 17, improvement of the orbit stability with a fast orbit feedback complementary to the slow orbit one, and preparation for top-up operation.
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| THPC063 |
First Frequency Maps for Probing the Non-linear Dynamics of SOLEIL
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3128 |
| |
- L. S. Nadolski, P. Brunelle, J.-P. Lavieville, P. Lebasque, A. Nadji, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette
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SOLEIL is a 2.75 GeV third generation synchrotron light source delivering photons to beam-lines since January 2007. With a 3.7 nm.rad horizontal emittance, its optics is based on a strong focusing lattice. Large on- and off-momentum apertures are required in order to provide good injection efficiency and as large as possible beam lifetime. It is then fundamental to be able to understand the limitations of these key figures. In order to probe the transverse non linear dynamics two pinger magnets have been installed into the injection straight section during last summer shutdown period. In this paper, their calibration will be described. Then first comparisons between modeled and real machine will be given for betatron tune shifts with amplitudes, and frequency maps. To end the non linear impact of insertion devices on beam dynamics will be discussed.
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| THPC064 |
Use of LOCO at Synchrotron SOLEIL
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3131 |
| |
- L. S. Nadolski
SOLEIL, Gif-sur-Yvette
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SOLEIL is a 354 m long 2.75 GeV third generation synchrotron light source delivering photons to beam-lines since January 2007. This paper will discuss in details the first attempts using LOCO code and problems encountered due to the storage ring lattice compactness. The introduction into the code of constraints on the quadrupole gradient variations gave tremendous improvements. The convergence is satisfactory, beta –beatings are reduced from 5% to below 1% RMS in both planes. Restoring the symmetry of the lattice enhanced the performances of the storage ring. In the last part, different ways of using LOCO as a powerful diagnostics tool will be given.
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| THPC065 |
Orbit Stability Status and Improvement at SOLEIL
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3134 |
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- L. S. Nadolski, J. C. Besson, F. Bouvet, P. Brunelle, L. Cassinari, J.-C. Denard, J.-M. Filhol, N. Hubert, J.-F. Lamarre, A. Loulergue, A. Nadji, D. Pedeau, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette
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SOLEIL is a 2.75 GeV third generation synchrotron light source delivering photons to beam-lines since January 2007. Stability of the beam-line source points is crucial for the user experiments. Typically this stability has to be below one tenth of the transverse beam sizes. This is challenging especially in the vertical plane leading to sub-micrometer values. This paper will describe the position stability achieved today without and with the slow orbit feedback. Impact of different noise sources and present limitations will be described. To end an improvement strategy will be given for short and medium terms.
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| THPC115 |
Commissioning of SOLEIL Fast Orbit Feedback system
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3248 |
| |
- N. Hubert, L. Cassinari, J.-C. Denard, J.-M. Filhol, N. Leclercq, A. Nadji, L. S. Nadolski, D. Pedeau
SOLEIL, Gif-sur-Yvette
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The Fast Orbit Feedback system at SOLEIL is fully integrated into the BPM system equipped with Libera modules. Indeed, the correction algorithm has been embedded into the Libera FPGA which directly drives the power supplies of dedicated air coil correctors. The beam position measurements of the 120 BPMs are distributed around the storage ring by a dedicated network. Then, the correction is computed and applied at a rate of 10 kHz to 48 correctors installed over stainless-steel bellows, on each side of every straight section. The BPM system has been operational for some time. The fast orbit feedback system is in its commissioning phase. The design and first results of the latter are reported.
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