| Paper | Title | Page |
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| MOPEA006 | Operation and Performance Upgrade of the SOLEIL Storage Ring | 73 |
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| SOLEIL delivers photons to 26 beamlines and 3 new ones are under construction together with the femtoslicing project. Up to 5 filling patterns are available for the users including a low alpha mode; all of them are in Top-up injection. The beam current for the users has been increased to 430 mA in the multibunch mode. The Storage Ring (SR) is running with a new optics incorporating an additional quadrupole triplet in one long straight section. The beam position stability remains excellent. Vertical positions from the dipole X-BPMs have been included in the orbit feedbacks loop with very encouraging results. A feedback loop maintaining the emittance coupling close to 1% for any Insertion Devices (IDs) configuration has been implemented. Up to 25 very diverse IDs are now installed on the SR, and several others are under design or construction. In house developments are being carried out in several domains such as construction of SR dipole power supply spare and of 70 kW-500 MHz solid state amplifiers, design of a pulsed multipole magnet for injection, and a Robinson wiggler, as well as a feasibility study of a local reduction of the emittance in one of the long straight sections. | ||
| MOPEA007 | Study of Lower Emittance Optics Using Multi-Bend-Achromat Lattice at SOLEIL | 76 |
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| In the framework of a future upgrade of the SOLEIL 354 m long and 2.75 GeV storage ring, a series of lattice studies has been launched to aim at reducing by an order of magnitude the current 4 nm.rad horizontal emittance. In this exercise, the main constraint imposed is to leave all the existing 24 straight sections for insertion devices untouched. In the previous study (presented at IPAC 2012), the possibility of using superbends and exploiting their longitudinal dipole field variation was pursued in lowering the emittance, finding solutions with a horizontal emittance in the sub nanometer range. In the present study, the use of MBA (Multi-Bend-Achromat) lattice is explored, which is widely recognized today as the optimal lattice in reaching an ultra-low emittance. The study aims to clarify the adaptability of the MBA and the range of attainable emittance for the SOLEIL ring, in view particularly of the short straight sections existing in half of the original DBA cells in between the dipoles. The possibility of combining the previously obtained superbend solutions with the MBA lattice is also examined. | ||
| MOPWO004 | Simulations and Studies of Electron Beam Dynamics under Compton Back-scattering for the Compact X-ray Source ThomX | 888 |
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Funding: This work is supported by the French "Agence Nationale de la Recherche" under reference ANR-10-EQPX-51, and also by grants from Région Ile-de-France, Université Paris-Sud and IN2P3/CNRS. In this article are presented beam dynamics investiga- tions of a relativistic electron bunch in the compact storage ring ThomX (50 MeV), which is under construction at LAL to produce hard X-ray using Compton Back-Scattering (CBS). The effect of CBS has been implemented in a 6D tracking code. In addition to CBS, the influence of lattice non linearities and various collective effects on the flux of scattered Compton photons is investigated. |
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| WEPEA003 | Dipole Fringe Field Effects in the ThomX Ring | 2504 |
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| Thom-X is a 50 MeV compact ring based on the Compton back-scattering which is being built in LAL, France. With a very short bend radius of 0.352 m, the nonlinear effects of the dipole fringe fields become critical to the beam dynamic . This paper compares the modelings of the dipole fringe field using four popular codes: MadX, Elegant, BETA, and Tracy3, and then discuss the proper model to have consistent results between the analytical calculation and the symplectic tracking of the Thom-X ring. | ||
| WEPFI005 | Simulations and RF Measurements of the Fundamental and Higher Order Modes of the ThomX 500 MHz Cavity | 2711 |
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The RF system of the ThomX* storage ring consists in a 500 MHz single cell copper cavity of the ELETTRA type, powered with a 50 kW CW solid state amplifier, and the associated Low Level RF feedback and control loops. The low operating energy of 50 – 70 MeV makes the impedances of the cavity higher order modes (HOMs) particularly critical for the beam stability. Their parasitic effects on the beam can be cured by HOM frequency shifting techniques, based on a fine temperature tuning and a dedicated plunger. A typical cavity temperature stability of ± 0.05°C within a range from 35 up to 80 °C can be achieved by a precise control of its water cooling temperature. On the other hand, the tuning of the cavity fundamental mode is achieved by changing its axial length by means of a mechanical tuner. In order to insure a fine control of the HOM frequencies, a good knowledge of their characteristics is mandatory. The main parameters of the fundamental and of the HOMs up to 4 GHz have been calculated using the HFSS and CST MWS codes. Preliminary measurements results have been obtained and show a good agreement with the simulations.
* A.Variola, “The ThomX Project”, Proceedings of IPAC2011, San Sebastián, Spain |
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