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Nadji, A.

Paper Title Page
WEPC093 Finalized Design of the Pulsed Magnets and their PS for SESAME Ring Injection 2210
 
  • S. Varnasseri, A. Nadji
    SESAME, Amman
  • J.-P. Lavieville, P. Lebasque
    SOLEIL, Gif-sur-Yvette
 
  The design of the SESAME storage ring injection pulsed magnet systems have been improved in order to take benefit of the most recent realizations in Synchrotrons. These pulsed systems are optimised for the injection into the 2.5GeV storage ring of the 800 MeV electrons beam prepared by the Booster. The septum magnet is based on a direct driven septum technology, out of vacuum, with a thin vacuum chamber of rectangular cross section permitting to get a good field transverse homogeneity. The four kicker magnets will be of the window frame geometry, around a racetrack alumina vacuum chamber, integrating a forced air cooling in order to avoid significant thermal heating due to the stored beam. These magnets can be opened for backup and will be completely CEM shielded. Their pulsed power supplies will be built based on solid-state HV switches, even for short half-sine pulses generation.  
WEZG02 Commissioning of an Accelerator: Tools and Management 1926
 
  • A. Nadji
    SOLEIL, Gif-sur-Yvette
 
  During the life of an accelerator project, the commissioning is a very important and exciting phase. It is preceded by a long period of design, calculations, magnetic measurements, installation, and alignment. We want the commissioning stage to be successful and fast; that is, attaining rapidly the set goals and make the machine available for impatient users. This paper summarizes the experience of several commissioning phases for different types of accelerators such as SNS, JPARC, and LHC, as well as synchrotron light sources such as DIAMOND, SOLEIL, and SSRF. The importance of preparation for commissioning on both technical and personnel levels will be covered. We will also talk about the concept of stages, anticipation of problems, and the early involvement of many specialists in addition to accelerator physicists and future accelerator operators. Furthermore, we will outline the importance of having a command control that is practical, fast, and has the capacity to offer high level automated applications. Finally, we will discuss the indispensable role of diagnostics for the first injection and first turns of the beam.  
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WEPC048 Experimental Characterization of the Insertion Device Effects on Beam Dynamics at SOLEIL 2097
 
  • P. Brunelle, C. Benabderrahmane, F. Briquez, O. V. Chubar, O. Marcouillé, F. Marteau, A. Nadji, L. S. Nadolski
    SOLEIL, Gif-sur-Yvette
 
  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.  
WEPC102 Commissioning of the Electromagnetic Insertion Devices at SOLEIL 2237
 
  • 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
 
  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.  
WEPC107 Observation and Interpretation of Dynamic Focusing Effects Introduced by APPLE-II Undulators on Electron Beam at SOLEIL 2249
 
  • O. V. Chubar, P. Brunelle, M.-E. Couprie, J.-M. Filhol, A. Nadji, L. S. Nadolski
    SOLEIL, Gif-sur-Yvette
 
  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.  
WEPC016 Operation Status and Performances Upgrade on SOLEIL Storage Ring 2022
 
  • 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
 
  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.  
WEPC055 General Status of SESAME 2115
 
  • H. Tarawneh, T. H. Abu-Hanieh, A. Al-Adwan, M. A. Al-najdawi, A. Amro, M. Attal, D. S. Foudeh, A. Kaftoosian, T. A. Khan, F. Makahleh, S. A. Matalgah, A. M. Mosa Hamad, M. M. Shehab, S. Varnasseri
    SESAME, Amman
  • A. Nadji
    SOLEIL, Gif-sur-Yvette
 
  An update of the status of SESAME is presented. SESAME is a third generation light source facility under construction in Allan, Jordan. The storage ring electron beam energy is 2.5 GeV, the beam emittance is 26 nm.rad and 12 straight sections are available for Insertion Devices. The injector consists of a 22.5 MeV microtron and 800 MeV booster synchrotron, with a repetition rate of 1 Hz. The SESAME building has been handed over on Dec. 2007 and this note focuses on the upgrade and installation plans for the SESAME injector system during the 2008. In the meantime, preparations of technical specifications for most of the storage ring subsystems are in progress. In this note the conceptual design of the storage ring’s bending magnet, pulsed magnets and their power supplies, RF system, shielding wall and the cooling system are presented. The tendering of these components is expected by mid 2008.  
THPC063 First Frequency Maps for Probing the Non-linear Dynamics of SOLEIL 3128
 
  • L. S. Nadolski, P. Brunelle, J.-P. Lavieville, P. Lebasque, A. Nadji, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette
 
  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.  
THPC115 Commissioning of SOLEIL Fast Orbit Feedback system 3248
 
  • N. Hubert, L. Cassinari, J.-C. Denard, J.-M. Filhol, N. Leclercq, A. Nadji, L. S. Nadolski, D. Pedeau
    SOLEIL, Gif-sur-Yvette
 
  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.  
THPC065 Orbit Stability Status and Improvement at SOLEIL 3134
 
  • 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
 
  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.