The muon collider has great potential to facilitate multi-TeV lepton-antilepton collisions. Reaching a suitably high luminosity requires low-emittance high-intensity muon beams. Ionization cooling is the technique proposed to reduce the emittance of muon beams. The Muon Ionization Cooling Experiment (MICE) has demonstrated transverse emittance reduction through ionization cooling by passing the beams with relatively large emittance through a single absorber, without acceleration. The international Muon Collider Collaboration aims to demonstrate 6-D ionization cooling at low emittance using beam acceleration. Two siting options are currently considered for a Cooling Demonstrator facility at CERN, with proton-driven pion production facilitated by the Proton Synchrotron or the Super Proton Synchrotron. In this work, we use FLUKA-based Monte Carlo simulations to optimize the number of pions produced in the proton-target interactions and subsequently captured by a magnetic horn-based system. We explore the feasibility of different target and capture system designs for 14, 26 and 100 GeV proton beam energies.

Multipacting is a phenomenon arising from the emission and subsequent multiplication of charged particles in accelerating radiofrequency (RF) cavities, which can limit the achievable RF power. Predicting field levels at which multipacting occurs is crucial for optimizing cavity geometries. This paper presents a new open-source Python code for analyzing multipacting in 2D axisymmetric cavity structures. The code leverages the NGSolve framework to solve the Maxwell Eigenvalue Problem (MEVP) to obtain the cavity's resonant modes' electromagnetic fields. The relativistic Lorentz force equation governing the motion of charged particles is then integrated using the fields within the cavity. Benchmarking against existing multipacting analysis tools is performed to validate the code's accuracy and efficiency. The open-source nature of the code fosters further development and customization for specific applications.

IFMIF-DONES is an ESFRI facility based on a 5 MW deuteron accelerator currently under construction in Granada (Spain) as part of the European roadmap to fusion electricity. Its main goal is to characterize and qualify materials under a neutron field with an induced damage like the one faced in a fusion reactor, developing a material database for the future fusion nuclear reactors. Moreover, a list of medium neutron flux experiments in other irradiation areas for fusion and non-fusion applications have been identified previously and are under analysis. The construction phase was officially launched from March 2023, after setting up the steering committee for the DONES Program composed of several countries. To support the preparation of the key documentation and consolidate contributions from parties, a set of tasks is being developed within the framework of the new DONES Consolidation Phase project (DONES-ConP1). In this contribution, the main objectives of the project such as the drafting of the acceptance tests for the procurement, the first version of the irradiation plan for fusion and non-fusion applications, or the update of key project documentation will be discussed.

Modification of an arc-cell vacuum system (length 14 m) for the cell SR18 in the TPS storage ring is described, which includes (a) replacement of a new bending chamber (B1) with an increased vertical aperture from 9 to 18 mm to prevent the B1 chamber from being exposed to synchronous radiation from the upstream elliptically polarized undulator (EPU), and (b) incensement of three pairs of flanges to separate the old arc-cell vacuum system into four subsystems (S3, B1, S4, B2). In this paper, we will report the manufacturing processes, measurement data and vacuum tests of these vacuum chambers.

Superconducting materials, like V3Si, NbN, NbTiN and Nb3Sn, are potential alternatives to Nb for next generation thin film SRF cavities. In comparison to the Nb, their relatively high Tc could allow for operation at higher temperatures (≥ 4 K) and the higher critical field could lead to for higher accelerating gradients. We investigate optimum deposition parameters and substrates for V3Si, using single target physical vapor deposition (PVD). We report on the superconducting properties such as Tc and surface resistance using RRR and low power RF, stoichiometry using RBS, SIMS, XPS and EDX and surface quality using AFM and white light interferometry.

CERN is pursuing several initiatives to reduce its impact on the environment through an integrated approach to address all the objectives set by the relevant United Nations (UN) Sustainable Development Goals (SDG). In particular CERN is committed to respect the net-zero paradigm for future machines and has established a Sustainable Accelerators Panel to harmonize the approach to sustainability of the various studies for future accelerators. In this paper we will describe the efforts taken in managing responsibly our technical installations and the process we are setting up to perform the lifecycle assessment of the different future projects to better understand the main drivers of CO2 emissions in order to minimize them by design.

Non-evaporable getter (NEG) coatings are used in accelerator beamlines to create an area of distributed pumping, allowing less external pumps to be installed, and smaller diameter tubes to be used. Both giving way to greater space for magnet arrays to better control the beam within, allowing more efficient accelerators to be produced. To work, NEG coatings must be activated by heating to a set temperature for 24 hours. This temperature depends on the properties of the NEG coating, and requirements of the system. The coating is then able to pump residual gasses out of the vacuum system, until it becomes saturated and will once again need activating. Over its a lifetime, a NEG coating will be activated and saturated numerous times, each time reducing the available sites for molecules to diffuse to during activation. Thus, eventually, the NEG coating will lose its capability, and will no longer be able to reach the same pumping capacity from the same activation regime. This study investigates the limits of NEG lifetimes, looking at the effect of multiple activations on the same coating. Samples of diameter 35 mm and length 50 cm were characterized by CO and H2 injections, from which the sticking probabilities and NEG coating capacity could be obtained. The samples were activated numerous times to see any degradation of the NEG coating. The results will be presented and discussed at IPAC 2024.

The stretched-wire alignment technique is one method of magnet alignment for linear induction accelerators. The applications of the Stretched-Wire Alignment Technique (SWAT) have been implemented for aligning magnets/solenoids on the Scorpius linear induction accelerator which will be sited at the Nevada National Security Site and the Flash X-Ray (FXR) linear induction accelerator at Lawrence Livermore National Laboratory’s Contained Firing Facility. This article describes both systematic (repeatable) and random sources of background/noise as well as practical ways to either eliminate or mitigate them to acceptable levels. Systematic sources include reflections from wire ends, rapid sag due to ohmic heating of the wire, magnetic materials, and shot rate. Random sources include air currents, vibration of nearby equipment, mechanical stability of test equipment, and the instruments used to measure the wire motion. Mitigations include curve fitting and adaptive noise signal cancellation, and mechanical damping. Finite Element Analysis (FEA) was used to interpret results.

The Bonn Isochronous Cyclotron provides proton, deuteron, alpha and other light ion beams with a charge-to-mass ratio Q/A >= 1/2 and kinetic energies ranging from 7 to 14 MeV per nucleon. The beam is guided through a high-energy beam line (HEBL) to one of five experimental sites. The installation of the irradiation site for high-uniformity radiation hardness tests of Si detectors is now complete. Additionally, a neutron irradiation site will be commissioned soon. Here, a collimated neutron beam, generated by a stripping reaction of the deuteron beam in a carbon target, can be used for irradiation. To provide stable beam with constant optics for these experiments, the power supplies (PS) of all magnets in the HEBL will be replaced. The replacements must meet strict criteria regarding output current's stability, which were derived from measurements of the existing PS. In this spirit, a new corrector magnet PS system, enabling bipolar operation, PS/magnet operation safety/health and power consumption monitoring, is close to commissioning. Additionally, the cyclotron's extraction septum is upgraded to increase operation robustness. Here, an new antiseptum is designed together with a new septum blade holder, which is intended to be additively manufactured with the laser- powder bed fusion technique.

The 3D design of large accelerators like the Large Hadron Collider (LHC) requires coordination among equipment, services, and infrastructures. As numerous systems are designed, procured, and installed, 3D integration studies are important steps at any stages of a project, starting from the conceptual phase with space reservations, envelopes and interfaces, followed by the technical design phase managing the detailed and simplified 3D models, and finishing by the installation phase with follow-up of discrepancies. While the first phases serve to validate the accelerator configuration and design, the installation phase is followed by a reverse engineering process to verify the ‘as-built’ configuration, representing the final actual setup of the accelerator. At CERN, the 3D integration office for the accelerators assumes responsibility for collecting, aggregating, centralizing, and checking the 3D models provided by CERN design offices such as equipment owners, electrical, civil engineering, metallic structure, transport, handling, cooling, and ventilation services. This office manages 3D space, avoiding mechanical interferences before and during the installation phase. This paper describes the CAD, PDM and PLM methodologies used for 3D integration of the accelerators at CERN, highlighting their critical aspects and specificities.