Despite a shorter-than-scheduled physics run due to a hardware problem, the AD/ELENA antiproton complex delivered record beam intensities to the experiments during the 2023 run. This paper reviews the performance of both the CERN Antiproton Decelerator (AD) and the Extra Low ENergy Antiproton (ELENA) decelerator and their associated transfer lines. It presents the main improvements that allowed these record beam intensities to be delivered to the experiments. Emphasis is put on the optimization of the injection line, progress made on the stochastic and electron cooling performance, increased deceleration efficiency and stability, and the software tools used. Remaining issues and potential future improvements for the coming run will also be presented.

A central part of CERN’s Future Circular collider study (FCC) is a ~91 km circumference lepton collider and its injector complex. This contribution outlines the various kicker systems needed to transport the lepton beams from the electron source up to the collider dump system. The individual system requirements are presented, and the choice of design parameters and technology options for both, beamline elements and pulse generators are discussed. Potential challenges like the fast rise time of 50 ns for the damping ring kicker system working at 200 Hz repetition rate are highlighted, together with considerations on energy recovery. Ferrite loaded kicker magnet topologies are compared with system concepts employing strip lines. The paper concludes with a summary on the feasibility aspects and a recommendation for eventually needed prototype studies.

The Physics Beyond Colliders is a CERN exploratory study aimed to fully exploit the scientific potential of its accelerator complex. In this initiative, the Gamma Factory experiment aims to produce in the Large Hadron Collider (GF@LHC) high-intensity photon beams in the energy domain up to 400 MeV. The production scheme is based on the collisions of a laser with ultra-relativistic atomic beam of Partially Stripped Ions (PSI) circulating in a storage ring. The collision results in a resonant excitation of the atoms, followed by the spontaneous emission of high-energy photons. A Proof of Principle (PoP) experiment is being planned to study the GF scheme generating X-rays, in the range of keV, from lithium-like lead PSI stored at the CERN Super Proton Synchrotron (SPS). GF-PoP has undergone a series of exhaustive radiation effect studies in view of Radiation to Electronics (R2E) risks. With the use of FLUKA Monte Carlo code, the radiation environment in the laser room and its premises has been estimated during proton and PSI runs. Recorded data from beam instruments has been used to appropriately scale the computed results and to verify the compliance with general R2E limits.

In order to maximize the integrated luminosity of the future circular lepton collider (FCC-ee), a top-up injection scheme is required. Amongst the four operation modes of FCC-ee, the Z operation mode has the highest stored beam energy in the collider ring with about 20 MJ per beam. Consequently, it is for this mode that the injection scheme is primarily optimized and is the focus of this contribution. Due to the synchrotron radiation cone of the injected beamlet at the interaction point (IP), the conventional off-axis injection scheme is not favored. As for the on-axis injection, it necessitates an energy offset for the injected beam and sufficient dynamic aperture in the collider ring. However, the energy acceptance of collider ring is only around ±1% for the latest baseline lattice of the Z mode, making this scheme challenging. Therefore, an hybrid on- and off-axis injection scheme is proposed to satisfy the requirements of dynamic aperture and energy acceptance. This contribution introduces the concept and discusses the optimization process used to balance energy and position offset of the injection scheme.

A local H- /p source is operated at the CERN Extra Low Energy Antiproton (ELENA) decelerator for commissioning the ring and subsequent electrostatic transfer lines toward the experiments. For proper optics characterization, it is important to have a detailed knowledge of the H- beam parameters at the source. Phase space tomography techniques were applied to reconstruct the beam distribution at the measurement point, which was then tracked backward to the H- source using symplectic field maps to calculate the beam matrix. Due to the presence of an ion switch a highly non-linear behavior with significant deviation from the linear model was observed. The SIMPA tracking code allows EM fields in the transfer line to be treated continuously and as a whole.

The LHC Injectors Upgrade project at CERN optimized the injection accelerator chain to deliver proton intensities per bunch of 2.3e+11 ppb. Throughout 2023, the LHC was filled with up to 2464 bunches per beam using a hybrid injection scheme, involving up to 236 bunches per injection, with a maximum intensity per bunch of 1.6e+11 ppb. These beam parameters already revealed significant beam losses at the primary collimator in Point 7 during injection, with large fluctuations from fill to fill, limiting in several cases the machine performance. This contribution analyses the performance of the LHC during injection and discusses possible improvements.