Search

SOLEIL is both a 2.75 GeV third generation synchrotron light source and a research laboratory at the forefront of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. We present the performance of the accelerators delivering extremely stable photon beams to 29 beamlines. We report on the commissioning of a superbend magnet replacing a standard 1.71T dipole with a 2.84 T narrow peak permanent magnet-based dipole. It required local modification of the lattice to compensate linear and nonlinear optics distortions introduced by the new magnet field. The latest measurements made with a Multipole Injection Kicker are also reported. Work on the NEG test bench and its dedicated front-end for a 10 mm inner diameter vacuum pipe and other major R areas are also addressed in the frame of the SOLEIL upgrade., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Previous CDR studies for the SOLEIL Upgrade project have converged towards a lattice alternating 7BA and 4BA HOA type cells providing a low natural horizontal emittance value in the 80 pm.rad range at an energy of 2.75 GeV. This lattice adapts to the current tunnel geometry as well as to preserve as much as possible the present beamline positions. The TDR lattice is an evolution of the CDR one including longer short straight sections, better relative magnet positioning, and the replacement quadrupole triplets by quadruplets for improving flexibility of optics matching in straight section. The SOLEIL upgrade TDR lattice is then composed of 20 HOA cells with a two-fold symmetry, and provides 20 straight sections having four different lengths of 3.0, 4.2, 8.0, and 8.2 m. This paper reports the linear and the non-linear beam dynamic optimization based on intense MOGA investigations, mainly to improve the energy acceptance required to keep a large enough Touschek beam lifetime. Some future directions for performance improvement are discussed., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Injection into the SOLEIL upgrade storage ring is much more challenging compared to the case of the current ring. Thanks to the experience gained in the development, manufacture and commissioning of a Multipole Injection Kicker (MIK) on the MAX IV 3 GeV storage ring, the SOLEIL pulsed magnet team is currently developing new MIK magnets that will serve as the basis for the injection schemes in the upgrade storage ring. We then propose two kinds of injections: firstly, a betatron off-axis injection that should be compatible with the full-coupling storage ring tuning, and secondly, a synchrotron on-axis injection by creating a large horizontal dispersion bump at the injection point., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

SOLEIL is both a synchrotron light source and a research laboratory at the cutting edge of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. This French 2.75 GeV third generation synchrotron light source provides today extremely stable photon beams to 29 beamlines (BLs) complementary to ESRF. We report facility performance, ongoing projects and recent major achievements. Major R areas will also be discussed, and progress towards a lattice baseline for making SOLEIL a diffraction limited storage ring., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The SOLEIL upgrade project aims to replace the actual SOLEIL storage ring by a 4th generation light source. The project has just finished its conceptual design report (CDR) phase*. Compared to the SOLEIL storage ring, the upgraded storage ring design includes many new features of 4th generation light sources that will impact collective effects, such as reduced beam pipe apertures, a smaller momentum compaction factor and the presence of harmonic cavities (HC). To mitigate them, we rely on several damping mechanisms provided by the synchrotron radiation, the transverse feedback system, and the HC (Landau damping and bunch lengthening). This article presents a first estimate of the collective effects impact of the upgraded design., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

Previous MBA studies converged toward a lattice composed of 20 7BA solution elaborated by adopting the sextupole pairing scheme with dispersion bumps originally developed at the ESRF-EBS. It provided a low natural horizontal emittance value of 70-80 pm-rad range at an energy of 2.75 GeV. Due to difficulties to accommodate such lattice geometry in the SOLEIL present tunnel as well as to preserve at best the beamline positioning, alternative lattice based on HOA (Higher-Order Achromat) type cell has been recently investigated. The HOA type cell being more modular and possibly exhibiting larger momentum acceptance as well as low emittances, a solution alternating 7BA and 4BA cells was then identified as the best to adapt the current beamline positioning. The SOLEIL CDR upgrade reference lattice is then composed of 20 HOA cells alternating 7BA and 4BA giving a natural horizontal emittance of 80 pm-rad. The linear and non-linear beam dynamic properties of the lattice along with the possibility of horizontal off-axis injection at full betatron coupling are presented., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

International audience; The design for the upgrade of the SOLEIL third generation light source is progressing. At the present stage, different lattices are evaluated as possible candidates for the storage ring upgrade and an important factor for the comparison of their performances is the robustness against lattice imperfections. The strategy for this study consists in defining a set of misalignments of the lattice elements and field errors of the magnets that are expected to be attained after the commissioning, applying them to the lattice models and correcting them using response matrix based techniques. A dedicated algorithm was developed in Accelerator Toolbox in order to accomplish this procedure and compare the different lattices. In this paper the results of this study at the current state are presented, including the considered lattice imperfections, the correction method applied and the final performance of the lattices.

As the work on the design of the upgrade of SOLEIL storage ring advances, the study of the impact of Intra-Beam Scattering (IBS) on the equilibrium emittance is also progressing, showing a significant contribution of this effect. Different measures can be taken to mitigate the emittance dilution, like operating the machine with full transverse coupling and using harmonic cavities to increase bunch length. The calculation of the IBS effect needs then to take into account the different beam dynamics and its effect on the particle distribution. In this paper the current state of the ongoing study is presented, reporting on the results obtained for the different options considered, and comparing the results of different codes and their implicit assumptions., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

SOLEIL is both a synchrotron light source and a research laboratory at the cutting edge of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. This French 2.75 GeV third generation synchrotron light source provides today extremely stable photon beams to 29 beamlines (BLs) complementary to ESRF. We report facility performance, ongoing projects and recent major achievements. A significant work was performed in order to secure the operation of the two canted 5.5 mm in-vacuum cryogenic permanent magnet undulators (CPMUs). Major R&D areas will also be discussed, and progress towards a lattice baseline for making SOLEIL a diffraction limited storage ring., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

With permanent magnets undulator operation at cryogenic temperature, the magnetic field and the coercivity can be enhanced, enabling shorter periods with high magnetic fields. The first full scale (2 m long, 18 mm period) hybrid cryogenic undulator [1] using PrFeB [2] magnets operating at 77 K was installed at SOLEIL in 2011. Photon spectra measurements, in good agreement with the ex-pectations from magnetic measurements, were used for precise alignment and taper optimization. The second and third 18 mm PrFeB cryogenic undulators, modified to a half-pole/magnet/half-pole structure, were optimized without any magnet or pole shimming after assembly but mechanical sortings and some geometrical corrections had been done before assembly. A systematic error on individual magnets on the third U18 was also compensated. In-situ measurement benches, including a Hall probe and a stretched wire to optimize the undulator field at room and cryogenic temperature are presented. An upgrade of these in-situ benches will be detailed with the fabrication of a 15 mm 3 m long PrFeB cryogenic undulator at SOLEIL., Proceedings of the 60th ICFA Advanced Beam Dynamics Workshop on Future Light Sources, FLS2018, Shanghai, China

Each long SOLEIL beamline, ANATOMIX and Nanoscopium, takes a photon beam from an in-vacuum undulator with a minimum gap of 5.5 mm. The canted radiation sources are installed in a long straight section of the storage ring. The first closure of both undulators led to the severe damage of the downstream undulator in 2011. The reason for this incident has been investigated and clearly identified. A long-term project has enabled us to find a technical solution for a simultaneous operation of both undulators. A special angle fast interlock was designed and a dedicated photon absorber has been introduced at the entrance of the second undulator while keeping the impact on the beam performance as low as possible. The main technical steps will be reported with an interim solution put in place in spring 2015 and a final solution deployed and validated in May 2016., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The first optimization of the nonlinear beam dynamics of the SOLEIL synchrotron radiation light sources using Multi-Objective Genetic Algorithm is reported. After benchmarking ELEGANT against TRACY3, beam lifetime studies with the operation lattice and fine-tuning of the storage ring model, MOGA-ELEGANT was used to find the best settings of quadrupole and sextupole magnets in order to maximize the dynamic and momentum apertures used as proxies for the Touschek lifetime and the injection efficiency respectively. The solutions obtained after one month of computation in the high level computational cluster of SOLEIL using 200 CPUs are detailed. The improvement of the Touschek lifetime obtained with MOGA is confirmed by the beam-based experiments. The beam lifetime of the SOLEIL storage ring was increased experimentally by 40% as predicted by the simulations., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

In the community of synchrotron radiation facilities, multi-bend structure becomes the trend of the storage ring design toward lower emittance. For SOLEIL upgrade project, the 7BA-6BA hybrid structure is one of the current options. This paper puts the focus on the 7BA section. There are many degrees of freedom to tweak and many constraints to follow. Here, the idea is to search and build the linear lattice utilizing Multi-Objective Genetic Algorithm (MOGA), which is efficient dealing with higher dimension optimization problems. Within MOGA, subsidiary matchings are performed to ensure certain criteria when the new generation is bred. Delicate designs and manipulations of the objective functions are needed, in order to have a better convergence without being trapped in a local minimum. The results will be shown and discussed., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

Synchrotron SOLEIL has just turned 10 years since its commissioning. The 2.75 GeV facility is now delivering very stable photon beams to 29 beam lines. A total of 5 operation modes are available in top-up. Maintaining and updating the key performance metric remains a daily work facing both aging of components and tighter operation requirements. Low-alpha operation is attracting more beam lines leading us to an upgrade of the Booster (BOO) radiofrequency (RF) system in order to increase the injection efficiency into the storage ring (SR). The femtoslicing experiment is now in production for a hard X-ray beam line; a dedicated chicane has been installed for a second beam line in the soft X-ray regime. The two long canted beam lines can operate simultaneously at minimum gaps since May 2016 thanks to the introduction of a dedicated photon absorber and a fast angle interlock. R&D work in several areas will be reported. In parallel lattice design are in progress both for short term and long term evolution of the ring performance., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

Previous MBA studies converged to a combination of 7BA and 6BA structures, in terms of the target horizontal emittance of below 300 pm-rad, where the effect of anti-bends, dipole field values, and straight section lengths were investigated. Inspired by the successful lattice designs elsewhere adopting the interleaved sextupole scheme with dispersion bumps originally developed at the ESRF, the 7BA-6BA structures adopting this scheme are studied in details in parallel to those without it. The former aims at the horizontal emittance in the 200-300 pm-rad range with on and off-momentum dynamic acceptances sufficiently large for off-axis injection and good Touschek lifetime. The latter pursues the lower bound of the reachable horizontal emittance with quadrupole and sextupole strengths in the feasible range with maximum dynamic acceptance. The option of non-standard on-axis injection such as displacing the injected beam longitudinally is envisaged for the latter solutions. In both lattices, the numerical search using MOGA-based codes is employed extensively. The studies focus on the impact of linear optics and straight section lengths on the off-momentum and nonlinear properties., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

With the aim of delivering a lower horizontal emittance beam to the users of the present SOLEIL ring, a systematic lattice study is carried out. The goal is to discover feasible optics solutions having the horizontal emittance notably lower than the present value of 3.9 nm rad, while fulfilling all the physical requirements and without changing the current magnet structure in the lattice. The strategy adopted is a cell-wise optimization of the linear lattices in the two types of double-bend cells that constitute the SOLEIL ring. In the second step they are concatenated via finer matching. A global scan of the 5 quadrupole families for the search of stable solutions is performed. The statistical properties are given. One can easily select possible solutions without matching. For the second type of cell having 10 quadrupole families, another scan of quadrupoles and a matching using a quadrupole triplet are applied for linear optics characteristics. Finally, the nonlinear optimization is performed with modern nonlinear optimization algorithms., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

Previous studies indicated that adoption of a combination of 7 and 6BA cells in the existing SOLEIL ring enables reaching the target range of the horizontal emittance below 200 pm·rad as expected, in contrast to fewer dipole solutions such as a combination of 5 and 4BA studied earlier (IPAC 2014). However, the previous 7BA-6BA lattice resulted in having unacceptably strong gradients in quadrupoles and dipoles leading to high natural chromaticities. Several schemes that would allow for an improvement are explored, such as shortening the insertion device straight sections by one or two meters to create more space for the magnetic structure, lowering the dipole fields and the use of anti-bends as proposed by A. Streun. The effectiveness of each scheme is evaluated and the best combined use of them for SOLEIL is investigated. Ways to fulfil the constraints of the existing dipole beam lines are studied by introducing longitudinal gradient bends and/or multipole wigglers. The nonlinear optimisation to maximise the on and off-momentum apertures is made by using genetic algorithm-based numerical codes. A comparison of their performance and the obtained results are presented., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

The 2.75 GeV synchrotron light source SOLEIL (France) delivers photons to 27 beamlines and 2 new ones are under construction. The commissioning of the Femtoslicing operation mode involving two beamlines is in progress. The uniform filling pattern is now available to users with a 500 mA stored beam current. The operation of the two canted and long beamlines ANATOMIX and Nanoscopium both using in-vacuum insertion devices (IDs) as a photon source has been raising challenges still under investigation. Upgrades of crucial subsystem equipment like magnet power supplies, storage ring RF input power couplers, and solid state amplifiers are continuing. New user requests for beam stability are under upgrade consideration. Other projects for the storage ring are ongoing such as the design and construction of new insertion devices, new multipole injection kicker, localised small and round photon beam production, as well as R&D on 500 MHz solid-state amplifiers. In parallel first studies for a future upgrade of the machine have been progressing., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

Within the scope of a future major upgrade of the SOLEIL storage ring, presently having the energy of 2.75 GeV, the circumference of 354 m and the horizontal emittance of 3.7 nm.rad, towards a Diffraction Limited Storage Ring (DLSR), the present paper presents and discusses the outcomes of a series of studies launched to explore different possible scenarios for the magnet lattice arrangement, under the constraint of making the upgrade in the same existing machine tunnel. Two scenarios were presented earlier in this context, which both preserved all the existing free straight sections for insertions, though the bending magnet positions were not strictly conserved. The purpose of the extended studies is to explore, in particular, the range of horizontal emittance that can be reached by hypothetically removing some of the existing geometric constraints, such as suppressing or shortening partially the straight sections. The emittance range is equally studied by fulfilling rigorously all constraints. The dependence of the nonlinear properties of the magnet lattice on the linear optics is simultaneously investigated., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

The 2.75 GeV synchrotron light source SOLEIL delivers photons to 27 beamlines; 2 new ones are under construction together with the FEMTOSLICING project of which commissioning started in January 2014. Five filling patterns are available for the users in Top-up injection mode. The storage ring is running with an upgraded optics less sensitive to insertion device (ID) configurations and giving both better beam lifetime and injection efficiency. The beam position stability remains excellent with a focus on electron vertical beam-size stability for the new very long beamlines. A gating system during Top-up injection improves significantly the quality of the spectrum on an infrared beamline. Several heavy actions of maintenance and upgrades on crucial subsystem equipment are underway. Others accelerator projects are going on such as the design and construction of new IDs, new Multipole Injection Kicker, radiation damage studies as well as R&D on solid-state amplifiers., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

The W164 out-vacuum wiggler was designed and built at SOLEIL with the double goal of producing high energy photons for the PUMA beamline (10 keV to 70 keV) and to be used as a modulator for the FEMTOSLICING project. The insertion device requires simultaneously reaching low resonant energy (1.55 eV) and high critical energy of photons (above 10 keV), leading to the choice of high field and large periods. The 3.28 m long wiggler is composed of 20 periods of 164 mm made of NdFeB magnets and vanadium permendur poles. The required effective field for the FEMTOSLICING is 1.53 T and the maximum total field reaches 1.8T at the minimum gap of 14.5 mm. The small transverse size of the poles was optimized to minimize the magnetic forces (8 tons maximum) resulting, together with the large field produced at minimum gap, to a large vertical dynamic field integral (DFI) inside the horizontal physical aperture of the chamber. A dedicated permanent magnet system was designed, constructed and installed at both wiggler ends to cancel the DFI at minimum gap. The construction of the wiggler, the results of the magnetic measurements and the effects on dynamics measured on electron beam are presented., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

SOLEIL, the French 2.75 GeV high brilliance third generation synchrotron light source is delivering photons to 20 beam lines and is presently equipped with 17 insertion devices. Significant reduction of injection efficiency and beam lifetime are observed when using some undulator configurations in daily operation. Measurements on electron beam, such as beam lifetime versus RF voltage, have shown that the energy acceptance is strongly reduced by the combined non linear effects of the four U20 in-vacuum undulators and the HU640 10m long undulator used in linear vertical polarization mode. This paper will present the on and off momentum frequency map measurements that have been performed in order to investigate such effects. The reduction of the on momentum dynamic aperture in the presence of the U20 undulators is confirmed. The off momentum frequency map measurements confirm that the energy acceptance of the bare machine is very large as predicted by tracking calculations, and clearly exhibit the strong energy acceptance reduction due to undulators., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The SOLEIL synchrotron light source is now delivering photons to 20 beamlines with a current of 400 mA in top-up mode. The long and short term H and V beam position stabilities are in the range of one micron thanks to the efficient slow and fast orbit feedbacks, and to the improved tunnel temperature regulation. The bunch by bunch transverse feedback is running with two independent H and V loops. To enable canted undulator implementations, a 3 magnet chicane has been installed in a medium straight whereas an additional triplet of quadrupole was inserted in the middle of a long straight to create a double low vertical beta. 17 insertion devices are now installed in the storage ring, 2 will be added early 2010, 8 are under construction, including a cryogenic undulator. Following the significant progression of the vacuum conditioning, the lifetime is now mainly Touchek limited. An electron bunch slicing set-up is also being installed to provide 100 fs long X-rays pulses to two existing beamlines. ~4500 hours will have been delivered in 2009 to the Beamlines with an availability above 96 % thanks to the very reliable operation of the unique SOLEIL RF system., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The production of high fluxes in the hard X-rays region is a major issue on medium energy storage rings. It requires the installation of Insertion Devices with high magnetic field and a large number of periods. The construction of a superconducting wiggler has been first envisaged but reveals to be maintenance constraining, much more complex and expensive than the permanent magnet technology. A small gap in vacuum wiggler composed of 38 periods of 50 mm has been preferred. The compact magnetic system allows to produce in a limited space a magnetic field of 2.1 T in a small gap of 5.5 mm, whereas an auxiliary counterforce system based on non-magnetic springs compensate the magnetic forces (up to 8.5 Tons) acting between magnet arrays. The gap between jaws and the mechanical deformations have been controlled and corrected. Magic fingers corrections have been also performed to reduce the integrated multipoles and to minimize the 2nd order integrals resulting from the tight width of the wiggler poles. This paper presents the design of the wiggler, the construction, and the results of the measurements after magnetic corrections., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The design for the upgrade of the SOLEIL third generation light source is progressing. At the present stage, different lattices are evaluated as possible candidates for the storage ring upgrade and an important factor for the comparison of their performances is the robustness against lattice imperfections. The strategy for this study consists in defining a set of misalignments of the lattice elements and field errors of the magnets that are expected to be attained after the commissioning, applying them to the lattice models and correcting them using response matrix based techniques. A dedicated algorithm was developed in Accelerator Toolbox in order to accomplish this procedure and compare the different lattices. In this paper the results of this study at the current state are presented, including the considered lattice imperfections, the correction method applied and the final performance of the lattices., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

SOLEIL is the French 2.75 GeV high brilliance third generation synchrotron light source delivering photons to 20 beamlines with a current of 400 mA in multibunch or hybrid modes, and 60 mA in 8 bunch mode. There are already 17 insertion devices installed and 9 others are planned in the next 2 coming years. Among them, two canted in vacuum insertion devices are planned, for the Nanoscopium and Tomography beamlines, and will be accommodated in a 12 m long straight section, with a 6.5 mrad separation angle. These ~150 m long beamlines will exploit the high brilliance and coherence characteristics of the X-ray (5-20 keV) beam both for diffraction limited focusing and for contrast formation. To provide low vertical beta functions at each undulator, an extra triplet of quadrupoles was added in the middle of the section. We present here the lattice implementation footprint, the different working point under investigations as well as the first results of the measurements on the machine performances., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan