A new design of fast wire scanner was installed in the CERN injector complex as part of the upgrades linked to the High-Luminosity LHC Project. Initial operations with these beams were good, but during the planned intensity ramp-up one early 2023, all four SPS scanners failed at the same time. An urgent program was put in place to understand and address this failure with experts from across the accelerator fields. Many measurements and simulations were performed and solutions implemented. This paper gives an overview of the issues seen, understanding and mitigations put in place to allow the instrument to perform at the maximum planned operational intensities.

Circular muon colliders provide the potential to explore center-of-mass energies at the multi-TeV scale within a relatively compact footprint. Because of the short muon lifetime, only a small fraction of stored beam particles will contribute to the physics output, while most of the muons will decay in the collider ring. The resulting power carried by decay electrons and positrons can amount to hundreds of Watt per meter. Dedicated shielding configurations are needed for protecting the superconducting magnets against the decay-induced heat and radiation damage. In this paper, we present generic shielding studies for two different collider options (3 TeV and 10 TeV), which are presently being explored by the International Muon Collider Collaboration. We show that the key parameter for the shielding design is the heat deposition in the magnet cold mass, which will be an important cost factor for facility operation due to the associated power consumption.

As part of the International Muon Collider study, a beam vacuum window is being developed at CERN. It is required for the final cooling, where the charged particles travel from the vacuum chamber to the absorber; here, the beam loses momentum to cross a second window entering in a RF cavity that increases the longitudinal momentum. The best absorber for the final cooling is hydrogen. As the absorber should be installed inside a high field focusing solenoid, the hydrogen density should be as high as possible, ideally liquid or high pressure gas, to have a reasonable solenoid length. To evaluate the performance of the window, it is necessary to study the tightness at cryogenic temperatures, resistance to burst, high temperature and beam-induced damage. The main objective of the proposed work is to design and validate a versatile bulge test setup for the mechanical characterization of thin windows at different pressures and temperatures to cover all operating conditions, from 77 K to 293.15 K and ideally above. Due to the low thicknesses, a non-contact measuring technique based on a confocal chromatic sensor is proposed.

Following the successful completion of the LHC Injectors Upgrade (LIU) project, since 2021 the Proton Synchrotron (PS) Booster has served the LHC injector chain with protons at an increased kinetic energy of 2 GeV. An upgrade of the ISOLDE (Isotope Separator On-Line DEvice) facility has long been considered to produce radioactive ion beams with a higher energy proton driver beam. A Consolidation and Improvements programme is presently underway to maintain ISOLDE’s position as a world-leading ISOL facility in the decades to come, with activities planned during the upcoming Long Shutdown 3 (LS3) (2026 - 28) and beyond. This contribution details a study to upgrade the beam line from the PS Booster to ISOLDE to operate between 1.4 and 2 GeV, and to increase the power of the proton driver in the future, assuming the replacement of the two beam dumps behind the facility’s production targets.