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In the first year of operation of the EBS storage ring, online nonlinear dynamics optimisations were performed to increase the Touschek lifetime. Several sextupole, octupole and skew quadrupole knobs have been studied in simulations and tested in the machine. A fast optimisation procedure has been defined and it is followed at each machine restart. The knobs and the optimisation procedure are described in the paper. As a result, up to 41 h Touschek lifetime in nominal multi-bunch mode have been achieved., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The EBS 6 GeV electron storage ring recently commissioned at ESRF, in Grenoble, France, is still operated using the old injector hardware. It is now one of the limiting factor of the facility. The large horizontal emittance of the booster beam affects injection efficiency, preventing from reaching 100% transfer efficiency between the 299.8 m long booster and the storage ring. Different lattice modifications going from minor optics changes to full machine renewal are considered . In this paper we will discuss different options of a "light" upgrade of the FODO lattice, keeping the RF system, vacuum chamber, power supplies, and most of the magnets. The upgrade then consists in creating a few new quadrupole families in the straight section vicinity and remove them from the main QF/QD families., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

A special session at eeFACT’22 reviewed the electrical power budgets and luminosity risks for eight proposed future Higgs and electroweak factories (CCC, CEPC, CERC, CLIC, FCC-ee, HELEN, ILC, and RELIC) and, in comparison, for a lepton-hadron collider (EIC) presently under construction. We report highlights of presentations and discussions., Proceedings of the 65th ICFA Advanced Beam Dynamics Workshop on High Luminosity Circular e+e- Colliders, eeFACT2022, Frascati, Italy

The ESRF-EBS is the first 4th generation source making use of the Hybrid Multi-Bend Achromat (HMBA) lattice cell, reaching an equilibrium horizontal emittance of 140 pm.rad in user mode (insertion devices (ID) gaps open). The injection in the storage ring (SR) is conducted with a short booster, operated off-energy. The RF frequency is increased compared to the nominal one to put the beam on a dispersive orbit, thus going off-axis in quadrupoles. The induced dipolar feed down effects reduce the booster horizontal emittance. The same strategy is extended to the ESRF-EBS SR, for an expected emittance reduction of about 20 pm.rad. A first approach shifts the RF frequency by +300 Hz to operate at -1% energy offset. Optimal quadrupole and sextupole settings are defined for this off-energy operation based on simulations. The settings are then tested in the SR in terms of dynamic aperture and injection efficiency., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

DAΦNE, the Frascati lepton collider, has completed the preparatory phase in order to deliver luminosity to the SIDDHARTA-2 detector. DAΦNE colliding rings rely on a new interaction region, which implements the well-established Crab-Waist collision scheme, and includes a low-beta section equipped with newly designed permanent magnet quadrupoles, and vacuum components. Diagnostics tools have been improved, especially the ones used to keep under control the beam-beam interaction. The horizontal feedback in the positron ring has been potentiated in order to achieve a higher positron current. Luminosity diagnostics have been also updated so to be compatible with the new detector design. The commissioning was initially focused on recovering the optimal dynamical vacuum conditions, outlining alignment errors, and optimizing ring optics. For this reason, a detuned optics, featured by relaxed low-b condition at the interaction point and Crab-Waist Sestupoles off, has been applied. In a second stage a low-b optics has been implemented to test collisions with a preliminary setup of the experiment detector. Machine preparation and the first luminosity results are presented and discussed., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The ESRF-EBS storage ring, successfully commissioned in 2020, operates the HMBA lattice, first proposed in * and then adopted in several recent upgrade programs. The successful and timely commissioning of the storage is in large part due to the excellent optics control achieved over that period. Design performance were obtained with lower than predicted correction strengths, localized for the most part in the vicinity of sextupoles. This remarkable behavior is not only the result of the corrective actions taken during the commissioning but also of the extremely accurate conception and alignment of the machine. This report summarizes the steps that lead to the present performances and discusses their stability over time., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The ESRF operates a 6 GeV 4th generation light source, the ESRF-EBS. This storage ring is the first to implement the Hybrid Multi-Bend Achromat lattice (HMBA). The HMBA lattice provides a reduction of the horizontal emittance of approximately a factor 30 with respect to the former Double Bend Achromat (DBA) structure, considerably improving the brilliance and transverse coherence of the ESRF accelerator complex while maintaining large horizontal acceptance and excellent lifetime performance. In this report, the characteristics of the HMBA lattice will be reviewed and the beam commissioning results and first operation experience of the new ESRF storage ring will be presented., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The European Synchrotron Radiation Facility - Extremely Brilliant Source (ESRF-EBS) is a facility upgrade allowing its scientific users to take advantage of the first high-energy 4th generation light source. In December 2018, after 30 years of operation, the beam stopped for a 12-month shutdown to dismantle the old storage ring and to install the new X-ray source. In December 2019, the first beam was stored and accumulated in the storage ring, allowing the vacuum conditioning and tuning to be started. The beam was delivered to beamlines in March 2020 for their commissioning. On 25 August, the user programme was restarted with beam parameters very close to nominal values. In this report, the milestones and key aspects of the return to user-mode operation are presented and discussed., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The Low Emittance Muon Accelerator~(LEMMA) aims at producing small emittance muons from positron annihilation with electrons in a target. Given the low cross section of the production process, a large number of positrons on the target are required, exposing it to high power deposition and the beam to large degradation because of multiple scattering and bremstrahlung. A multi-target IP, and multi-IP line has been studied to reduce the power deposition per target and the degradation of the positron beam while preserving the number of muon pairs produced. The lattice copes with the focusing and transport of three beams at two different energies, the positron beam at 45 GeV, and µ⁺+ and µ⁻ beams at 22.5~GeV. Studies on the beam dynamics, number of targets, material and thickness of the targets are reported in this paper., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The design of a future multi-TeV muon collider needs new ideas to overcome the technological challenges related to muon production, cooling, accumulation and acceleration. The Low Emittance Muon Accelerator (LEMMA) concept *,** presents in this paper an upgraded layout of a positron driven muon source. The positron beam, stored in a ring with high energy acceptance and low emittance, is extracted and driven in a push-pull configuration to a multi-target system, to produce muon pairs at threshold on the target’s electrons. This solution alleviates the issues related to the power deposited and the integrated Peak Energy Density Deposition on the targets. Muons produced in the multi-target system will then be accumulated in many parallel rings before acceleration and injection in the collider. A special multi-target line lattice has been designed to cope with the focusing of both the positron and muon beams. Studies on the number, material and thickness of the targets have been carried out. A general layout of the overall scheme and a description is presented, as well as plans for future R, Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The commissioning of the ESRF-EBS storage ring will start in December 2019 ultimately providing a horizontal emittance of 130 pm, 30 times lower than the present one. Due to the reduced beam lifetime top-up operation will be required for all operating modes. Transparent injection, i.e. with negligible perturbations on the stored beam, is necessary to allow continuous data acquisition for beam lines experiments. Several options have been considered at ESRF to reduce these perturbations down to a fraction of the rms beam size: i) new kickers power supplies with slow ramping time to facilitate active compensation are under development and will be implemented in the coming years ii) in parallel, long term solutions using non-linear kickers and longitudinal on-axis injection have been investigated., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

In 1988, eleven European countries joined forces to build the European Synchrotron Facility in Grenoble [France]. The ESRF was the first third-generation light source worldwide. After 30 years of innovation and user operation, the present storage ring was shut down to leave room for a new and brighter source. This paper describes the evolution of the facility from its origin to the Ex-tremely Bright Source (EBS). Firstly, the operational aspects including reliability and beam modes are consid-ered. This is followed by the presentation of the progress of lattice and the implementation of top-up. Finally, the development of the radio frequency and vacuum systems are discussed. To conclude, the lessons learned from 30 years operation are summarized, especially in view of EBS., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

In March 2018 DAΦNE, the Italian electron-positron Phi-factory based on the Crab Waist collision concept, has successfully completed the challenging experimental run for the KLOE-2 detector. At present, installation of the SIDDHARTA-2 detector is underway in order to start data acquisition with the new experimental apparatus in the year 2019. In this paper we review the collider performances during the KLOE-2 run in terms of the achieved beam currents, the peak and integrated luminosity and encountered beam dynamics challenges. The design and development work done in view of the SIDDHARTA-2 operation is presented and discussed., Proceedings of the 26th Russian Particle Accelerator Conf., RUPAC2018, Protvino, Russia

Dafne, the Italian lepton collider, is running since more than a decade thanks to a radical revision of the approach used to deal with the beam-beam interaction: the Crab-Waist collision scheme. In this context, the collider has recently completed a long term activity program aimed at providing an unprecedented sample of data to the KLOE-2 detector, a large experimental apparatus including a high intensity solenoidal field strongly perturbing ring optics and beam dynamics. The KLOE-2 run has been undertaken with the twofold intend of collecting data for rare decay flavor physics studies, and testing the effectiveness of the new collision scheme in the presence of a strongly perturbing experimental apparatus. The performances of the collider are reviewed and the limiting factors discussed along with the preparatory phase activities planned to secure a new collider run to the SIDDHARTA-2 experiment., Proceedings of the 62th ICFA ABDW on High Luminosity Circular e$^+$e$^-$ Colliders, eeFACT2018, Hong Kong, China

DAΦNE, the Frascati lepton collider working at the c.m. energy of the F resonance, continues to be a very suitable infrastructure to realize experiments aimed at studying elementary particles and nuclear physics. The motivations of this long lasting interest are related to the DAΦNE ability of increasing its performances in terms of luminosity thanks to the innovative Crab-Waist collision scheme. In this framework, a new run for the SIDDHARTA-2 experiment has been planned in the year 2019. The detector presently installed in the interaction region, KLOE-2, will be removed and a new low-beta session, equipped with new permanent magnets quadrupoles, will be installed. Diagnostics tools will be improved especially the ones used to keep under control the beam-beam interaction. The horizontal feedback in the positron ring will be potentiated in order to achieve a higher positron current. The design and development work done in view of the SIDDHARTA-2 run is presented and discussed., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The ESRF - the European Synchrotron Radiation Facility - is a user facility in Grenoble, France, and the source of intense high-energy (6 GeV) X-rays. In 2019, the existing storage ring will be removed and a new lattice will be installed in its place, dramatically reducing the equilibrium horizontal emittance. This 'fourth-generation' synchrotron will produce an X-ray beam 100 times more brilliant and coherent than the ESRF source today. The Extremely Brilliant Source (EBS) project was launched in 2015 and is now well underway, on track for its scheduled completion in 2020. The design is completed, the procurement in full swing, the assembly has started, and critical installation activities are being prepared. The current status, three years into the project, will be revealed, along with the expected performance of the accelerator and the technical challenges involved. This paper will focus on the implementation of the project., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

Very low emittance muon beams can be produced by direct annihilation of about 45~GeV positrons on atomic electrons in a thin target. With such a muon beam source, a mu+mu- collider can be designed in the multi-TeV range at very high luminosities. In this scheme two muon accumulator rings are foreseen to recollect the muon bunches that will be injected in the collider. We present in this paper the first consideration of the muon accumulator rings. Realistic muon beam emittance and energy spread coming from the muon target are described. Constraints on the accumulator ring requirements are derived., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The ESRF storage ring will be replaced by the Extremely Brilliant Source (EBS) in 2020 and the equilibrium emittance will decrease from the present 4 nmrad to 134 pmrad. The current injector system, composed by a linac and a synchrotron booster, will be used to inject into the new storage ring. To increase the injection efficiency in the new storage ring, three methods to reduce the horizontal emittance of the booster have been considered and tested. This paper presents the studies and achievements in terms of operation improvements and emittance reduction., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The ESRF Extremely Brilliant Source (ESRF-EBS) lattice model is updated to include three canted beamlines. The cells are modified where necessary to include 3-Pole Wiggler (3PW), 2-Pole Wiggler (2PW) and Short Bending Magnet (SBM) sources. Several lattices are obtained for the different stages that will bring from commissioning to operation with users. A scheme for tune modification keeping key optics knobs unchanged is proposed., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The European Synchrotron Radiation Facility (ESRF) is undergoing the second phase (2015-2022) of an Up-grade which concerns its infrastructure, beamlines and X-ray source. This paper reports on the present operational source performance, highlighting the most recent developments, and the preparation of the Extremely Brilliant Source project. The renovation of the injector and the recent operation in top-up mode are also detailed., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The ESRF-EBS project foresees the replacement of the existing bending magnets beamlines with different radiation sources: short bend, 2-pole wiggler or 3-pole wiggler. After describing the reasons for this choices the required modifications to the storage ring lattice are described in details for each case. The study of the impact of lattice errors is also addressed, leading to the definition of beamlines' alignment tolerances., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The Hybrid Multi Bend Achromat: from SuperB to EBS. The motivations and rationale at the basis of the Hybrid Multi Bend Achromat (HMBA) lattice and its evolution through the years are presented. Its implementation in the ESRF Extremely Brilliant Source (EBS) upgrade is also shown., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The ESRF storage ring injection and accumulation is performed using standard 4-kickers bump and septum magnet. Sextupoles are located within the injection bump leading to significant bump non-closure during the ramp-up and ramp-down and optics distorsion for both stored and injected beam. Introducing non-linearities in the kickers allows for compensation of the perturbation from these sextupoles. We report on the feasibility of adding eddy current screens to a standard kicker magnet design to generate a non-linear field and its recent application to mitigate the injection perturbations at the ESRF., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

International audience; The Double Triple Bend Achromat (DTBA) is a newly designed cell for a next generation 3 GeV synchrotron light source. DTBA is inspired by the Double-Double Bend Achromat (DDBA) cell designed for Diamond and originates from a modification of the ESRF HMBA 6 GeV cell, combining in this way the best characteristics of each lattice. The lattice achieves a natural emittance as low as 131 pm, together with a sufficient Dynamic Aperture (DA) for injection and lifetime. Two cells are designed with different end-drift lengths providing two different Long Straight Sections (LSS) for insertion devices, 5 and 7.5 m long, in addition to a new middle-straight section of 3 m. The characteristics of the lattice together with the results on emittance, DA and Touschek lifetime are presented after extensive linear and non-linear optimisations, with and without the presence of errors and corrections.

In the frame of the Extremely Brilliant Source project (EBS), studies dedicated to disturbances have been more intensively investigated. Engineering instabilities have two origins: mechanical and thermal. Major thermal issues are: - air conditioning presents a temperature ramp up of 2°C along the sector - storage ring requires a warm up period of 4 days for reaching a stable orbit These effects have been observed and corrected for 20 years. With EBS requirements, we need to identify these thermal effects in order to reduce the disturbances, thus improving more systematically the source stability. The study is lead by the comparison between the present and the new thermal system. To do so, it is necessary to evaluate the heat balance in this system, as well as to identify the thermal time constant of each component. FEA models have been performed to reveal sensitivity of these thermal issues. A full scale mock-up cell equipped with a prototype girder is measured with power cables inside. A FEA model was also developed for the present storage ring to analyse the air stream. Although investigations have already been developed, some others remain to be achieved by the end of 2016., Proceedings of the 9th Edition of the Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation Conference, MEDSI2016, Barcelona, Spain

In the Beam Delivery Systems (BDS) for linear colliders that have been designed or built, collimators (or scrapers) are used to suppress backgrounds due to the beam halo. Off-energy and off-axis particles are stopped on the collimator jaws, physically limiting the acceptance of the system. This concept does not scale well to higher beam energy, higher intensity or lower emittance. The increased beam density requires longer and more demanding collimator regions. In contrast, this paper studies the possibility of inserting non-linear optical elements into the Final Focus in order to effectively increase the acceptance of the system. This technique could make the traditional collimation scheme obsolete so that only protection collimators would be needed.

With the introduction of top-up operation at the ESRF it becomes important to reduce as much as possible any kind of perturbation seen by the users during injection. For this purpose, a novel technique to improve injection efficiency by shaping the horizontal beam phase space to better match the storage ring acceptance and hence reduce the duration of injections was developed. Theoretical concept, simulations and first experimental results are presented., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

The ESRF-EBS lattice model is updated to include the effect of magnetic lengths in dipoles, quadrupoles, sextupoles and combined function magnets. The effect of this modification and the updates to the injection cell are considered with particular focus on injection efficiency and Touschek lifetime. The solutions to introduce new sources of radiation suitable for the existing bending magnet radiation beamlines are also presented., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea