Recently exact Hamiltonian integrators have been added for drift, multipoles and dipoles in Accelerator Toolbox. This paper reports the tracking simulations benchmarks performed to compare with the results provided by MADX-PTC for four lattices: FODO, DBA, H7BA and FCC-HFD@Z. Tracking times are also reported for completeness. The agreement in 4D is complete while small discrepancies persist for 6D tracking. Fringe fields models were not included in the comparison and are known to be different for the two codes.

The vertical beam halo is the main limitation for very low gap operation of in-vacuum undulators at the ESRF EBS. The vertical halo is due to Touschek electrons with large energy deviation crossing some betatron resonances. The crossing of the resonances can transfer horizontal momentum to vertical momentum. The beam halo has been characterized and measured and different low halo optics have been studied and tested to allow the operation of the machine with lower in-vacuum undulator gaps.

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 storage ring 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. On 25th August 2020, the user program restarted with beam parameters very close to nominal values. Since then beam is back for the users at full operation performance and with an excellent reliability. This paper reports on the present operation performance of the source, highlighting the ongoing and planned developments and the sustainability efforts.

The ESRF-EBS storage ring is operated with constant vertical emittance at 10 pm. The emittance blow-up is obtained with a magnetic shaker exciting the beam with a noise in a range of frequencies including the betatron tunes. The amplitude of the shaker is tuned by a feedback depending on the measured emittance. The coherent oscillations given to the beam by the shaker at each turn become incoherent thanks to the chromaticity and the amplitude detuning. Simulations and measurements have been performed to assess the efficiency of the emittance blow-up as a function of the chromaticities.

The parallel beam based alignment technique developped at SLAC is applied for the EBS storage ring. The results are compared with the standard beam based alignment technique used for operation.

The ESRF-EBS injection is performed with a standard off-axis injection scheme consisting of two in-air septa S1/2, one in vacuum septum S3 and four kicker magnets K1 to K4 to generate the injection bump. We can achieve 80% efficiency with this scheme. Despite many modifications and adjustments which allow the reduction of the perturbation, some beamlines are still affected. The Non-Linear Kicker could be a solution to this problem because it acts only on the injected beam. This paper reports on the magnetic design of the Non-Linear Kicker, including the octupole like Magnetic field simulations, magnetic forces calculations and mechanical tolerance optimizations.

With a circumference of approximately 91 km, the Future Circular electron-positron Collider, FCC-ee, aims for unprecedented luminosities at beam energies from 45.6 to 182.5 GeV. A major challenge is reaching its design performance in the presence of magnet misalignments and field errors. The FCC-ee optics tuning working group studies all related aspects, and applies state-of-the-art techniques for beam-based alignment, commissioning simulations, beam threading, optics measurements and corrections, which are probed at numerous world-leading accelerator physics facilities. Advanced optics correction simulations include interaction-point tuning, magnetic tolerances are studied, and a new optics is under scrutiny. The current status of tuning simulations for different FCC-ee lattices is presented.

In autumn 2023, the FCC Feasibility Study underwent a crucial “mid-term review”. We describe some accelerator performance risks for the proposed future circular electron- positron collider, FCC-ee, identified for, and during, the mid-term review. For the collider rings, these are the collective effects when running on the Z resonance – especially resistive wall, beam-beam, and electron cloud –, the beam lifetime, dynamic aperture, alignment tolerances, and beam-based alignment. For the booster, the primary concern is the vacuum system, with regard to impedance and effects of the residual gas. For the injector, the layout and the linac repetition rate are primary considerations. We discuss the various issues and report the planned mitigations.

The European Synchrotron Radiation Facility (ESRF) presently operates with the Hybrid Multi-Bend Achromat (HMBA) lattice that features 𝛽-functions of 6.9 m and 2.7 m in the horizontal and vertical planes at the center of the straight sections. New optics were designed to increase the brilliance of beam lines with a single undulator placed at the center of the straight section. The reduction of the in-vacuum undulator gap and of the beta-functions both contribute to this increase. This paper reports on the optics beam commissioning results and experimental observation with the reduced in-vacuum undulator gap.