The Elettra 2.0 upgrade project requires the realization of a new storage ring that will replace the existing one of Elettra. The Elettra 2.0 optic, developed on the basis of the magnet feasibility studies, include a total of 552 iron-dominated electro magnets, with all sextupoles and octupoles equipped with additional coils to achieve the combined fields of corrector and skew quadrupoles. This paper reports all the latest magnetic and pre-engineered designs and the comparison with the main magnet prototype performances.

The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source, which started construction in 2019. The sextupole and octupole magnets in the storage ring of HEPS are divided into several groups, and each group of magnets shares one power supply. In the lattice design, magnets in the same group are identical, but the real magnets have errors, which violate the symmetry of the lattice. To optimize the performance of HEPS, it is necessary to carry out sorting of these magnets. By doing simulations with elegant, we studied the effect of sorting on the performance of the nonlinear beam dynamics. The details are presented in this paper.

During loss maps performed with beam at injection energy in the LHC with the high octupole and chromaticity settings used for multi-train operation, large beam losses were observed at an injection protection device (TDIS). Although these losses did not present a threat to machine operation or protection, reducing them is of high importance to improve machine performance. Various strategies were developed to mitigate these losses, such as octupole setting optimization at constant Landau damping and vertical tune reduction. Further optimization of collimator settings is also considered. Results of experimental tests and first simulations are reported here together with considerations for the future.

Studies of third-order chromaticity in the LHC during its initial two runs have consistently demonstrated a substantial discrepancy between the expected Q''' at injection and that observed in beam-based measurements. In 2022 during Run 3, for the first time, studies of Q''' have been complemented by measurements of chromatic detuning, being the momentum-dependence of amplitude detuning, and the decapole resonance driving term 𝑓1004. In this paper, these beam-based measurements are presented and compared to the magnetic model. Potential sources of the previously identified Q”’ discrepancy are discussed.

Chromaticity up to the third order in the LHC has been well observed in the LHC’s first and second operational runs, with regular beam-based measurements performed during commissioning and machine development. In previous runs however, no higher-order chromaticity could be observed. In 2022, dedicated collimators setups meant optics measurements could benefit from an improved range of momentum-offset for the chromaticity studies. This allowed the observation of fourth and fifth order chromaticity in the LHC at 450GeV for the first time. Measurements were performed for several machine configurations. In this paper, results of the higher order non-linear chromaticity are presented and compared to predictions of the LHC magnetic model.

Run 4 will be the first operational run of the LHC with full deployment of the upgrades from the High Luminosity (HL-LHC) project planned for 2026-2028 (Long Shutdown 3). The commissioning goals for the first run were defined to approach steadily the design beam current, while already fulfilling significant luminosity goals. Despite extensive operational experience already gained, intensity limitations due to electron cloud and/or impedance might require to further reduce beta* values from the very early stages. The paper presents various optics configurations considered under different Run4 scenarios together with their expected dynamic aperture.

The Swiss Light Source SLS will have a 15 months long shutdown starting in October 2023 in order to install the new storage ring SLS 2.0. While the procurement of large series of components like magnets, power supplies, RF, vacuum chambers, … has started, the design of more specific components like the thin septum, undulators or collimators, is close to completion. The main difficulties and challenges of SLS 2.0 are common to other diffraction limited storage rings: cross talk issues due to the very short distances between magnets and especially with permanent magnets, heat dissipation issues in the small aperture vacuum chambers due to synchrotron radiation and RF heating and in general beam instabilities issues due to wakefields perturbations. Components have been designed to withstand these constrains and this paper will give an overview of the key components design and first tests before installation.

The extraction inefficiency of the slow extraction process induces radioactivity in the area surrounding the electrostatic septum. Studies at the CERN Proton Synchrotron (PS) are investigating beam loss reduction techniques to improve the efficiency of the beams provided to the experiments of the East Area. Powering octupoles distorts the transverse phase-space of the extracted beam which can be exploited to maximize the number of particles in the field region of the septum with respect to the number lost on the septum. The effect of octupoles on the separatrices near the third-order resonance is simulated with MADX-PTC tools to observe phase space folding and to predict the multipole parameters needed to minimize beam loss. Experimental studies are performed to confirm the validity of the simulation models and to quantify the net benefit of using octupoles to improve the extraction efficiency.

Octupole magnets are a central mitigation method against the transverse collective instabilities expected for the high-intensity operation of the SIS18 and SIS100 synchrotrons in the FAIR project. For these beam parameters, the self-field space-charge effect dominates the betatron footprint, and strongly modifies the instability drive and the Landau damping properties. The space-charge tune shifts are related to all three incoherent amplitudes, and is an intrinsic interaction. We consider all these effects and study Landau damping of head-tail modes due to the combination of octupoles and space-charge. Using the data from experimental instability observations, and particle tracking simulations, we provide estimations for the expected high-intensity operation of the SIS synchrotrons.

Limited dynamic aperture which is in the consequence of strong nonlinearities in a low emittance storage ring, is a challenging issue from beam dynamics point of view. In the present study, we have applied three families of focusing and defocusing octupoles to the storage ring lattice with the aim of increasing dynamic aperture and beam lifetime . We have discussed different methods to optimize of the position and strength of octupoles so that each octupole family fights a specific resonance driving term.

Dynamic Aperture (DA) studies based on single-particle tracking simulations have proven to be a powerful tool for optimizing the performance of the Large Hadron Collider (LHC), as well as its future High-Luminosity upgrade (HL-LHC). The present paper presents the studies performed for the first year of HL-LHC operation at the beginning of the fourth operational run of the LHC. The main focus lies on the exploration of new optics scenarios such as flat optics, where the transverse beam sizes at the high-luminosity interactions points are not equal. Multi-parametric DA studies and Frequency Map Analysis are deployed to derive the best parameters for operation for the start and end of the luminosity leveling with flat optics.

The compensation of the long-range beam-beam interactions by DC wires is currently being investigated as an option for enhancing machine performance in the framework of the High-Luminosity LHC Project. In this paper, we report and comment on the potential of wire compensation during the first HL-LHC run. The results are based on numerical simulations and optimisations of the machine dynamic aperture varying the wire position and current, taking into account the latest optics and beam scenarios and the constraints imposed by the corresponding settings of the HL-LHC collimation system.

Fixed Field Alternating Gradient Accelerators (FFAs) that follow the conventional scaling law have – by definition – high order multipole components in their magnetic fields. It is the presence of these nonlinearities that in many cases determines several important properties of the machine, including amplitude-dependent tune shift and dynamic aperture. Consequently, understanding of the nonlinear dynamics in these machines can be critical to design and optimisation processes. Study of these properties is made challenging by the complicated nature of closed orbits in many FFAs and the presence of edge angle effects (which are exploited by design in certain lattice configurations, such as the F-D spiral design chosen as the baseline for the FETS-hFFA prototype ring). This poster presents a novel method of nonlinear analysis based on the combined application of harmonic analysis and truncated power series algebra-derived techniques.

Formulae to compute the footprint (amplitude-dependent detunings) and Resonance driving terms RDT, generated by long-range beam-beam collisions and wire correctors have been implemented in a Python code. The paper briefly outlines the method and code and provides several examples of its usage. The maximum extent of the footprint (in geometric sense) can be efficiently computed.

Several studies have been performed in the 2021 and 2022 runs to build a better understanding of the behaviour of the accelerator with high intensity beams. Transverse beam instabilities at injection energy are known from previous measurements and simulations to be a potential limitation to reach the LHC Injectors Upgrade (LIU) target beam intensity. This paper summarizes the limitations introduced by transverse instabilities and the experience gained during 2021 and 2022 runs. Special emphasis will be given to the vertical coupled-bunch instability predicted by simulations and observed for the first time after the Long Shutdown 2 (LS2) during the 2021 run. This instability together with the horizontal one, which has been deeply characterized before LS2, is expected to impose constraints on the chromaticity, octupole current and tune working point. The stabilization strategy at the LIU intensity has been demonstrated during the 2022 run. Beam lifetime and quality for the explored operational settings will also be discussed.

An air-core pulsed magnet named Ceramics chamber with integrated Pulsed Magnet (CCiPM) was developed as a fast dipole kicker at first. A prototype of a dipole CCiPM was designed and tested successfully at KEK Photon Factory (KEK-PF). Because of the feature of an air-core magnet, a CCiPM can also generate an octupole magnetic field for pulsed multipole magnet injection. Compared with the pulsed iron-core magnet, the CCiPM almost does not have eddy current effects which may induce the stored beam oscillation. One prototype has been developed for the beam injection at PF ring. To examine the performance of the octupole CCiPM, some experiments has been conducted such as durability test, current excitation test and magnetic field measurement to evaluate the mechanical performance and magnetic field quality. The design and experimental results will be reviewed.

The standard injection scheme of ILSF is composed of 2 septum and 4 kicker magnets installed in a 7-meter-long straight section. Further tuning of the 4 kicker devices to reduce perturbations has proven to be almost impossible since it requires having 4 identical magnets, electronics, and Ti-coated ceramic chambers. Different from pulsed dipole kicker magnets used in a conventional local-bump injection, the single nonlinear or multipole kicker provides a nonlinear distribution of magnetic fields, which has a maximum value off the axis where the injected beam arrives and a zero or near-zero value at the center where the stored beam passes by. So, here the designs of different multipole kickers, including sextupole, octupole, and a nonlinear kicker, have been investigated and compared.

High-order corrector magnets will be required for the magnetic system of the HL-LHC inner triplets. These magnets are based on a superferric design thus the saturation of the iron poles affects the field generated in the aperture, i.e., the magnetic transfer function shows a nonlinearity. One of the challenges for the operations of these magnets is to find a suitable fit of the magnetic transfer function able to predict the field generated, given the current, within the acceptable level of 1%. In the LHC, the magnet operations rely on a magnetic field model (FiDeL) for deriving the current level from the required field strength. This paper presents a first iteration of the field modelling for the new high-order corrector magnets.

Super Fragment Separator (Super-FRS) is the highest priority accelerator facility in construction of the FAIR at GSI, Darmstadt Germany. Super-FRS will provide desired exotic isotope beams to various experiment sites for fundamental researches. The high energy branch of Super-FRS will be the earliest to be built and will enable to execute the first experiment of FAIR. Key elements of the Super-FRS that large aperture superconducting dipole magnets and multiplets, which contain quadrupole magnets and corrector magnets, determine performance of the beam separator, are being manufactured and tested intensively. In Spain, super-ferric dipole magnets with combination of a warm iron yoke and a superconducting coil cryostat are manufactured, while bath-cooled multiplet cold masses in a large cryostat are produced in Italy. These magnets are transported to a dedicated test facility at CERN, Switzerland, for a qualification of the performance. The testing are executed by a GSI team in collaboration with CERN. The test results are fully assessed by GSI experts including beam optical evaluations and an acceptance decision is made. Accepted magnets are delivered to GSI and inspected at room temperature, and equipped with interface items to the accelerator infrastructure (pre-assembly) and stored for the installation into the FAIR building. We will report status of the Super-FRS sc magnet production, testing, as well as pre-assembly, highlight some findings and the measures.

The Super Separator Spectrometer (S3) is an experimental device dedicated to fundamental research in nuclear physics at GANIL laboratory in Caen, France*. S3 spectrometer was designed in the framework of SPIRAL2 in order to take full advantage of the very high intensity stable ion beam delivered by the superconducting linear accelerator, LINAC**. In November 2022, the first beam of Argon beam has been accelerated to an energy of 7 MeV/u by the LINAC, opening the door for S3 experimental program. In the meantime, the installation of the spectrometer is being finalized and is due to accept the first beams by the end of 2024, for commissioning. In order to achieve a mass resolution of 1/450 together with a high transmission, the superconducting magnets of S3 are designed with a large warm-bore aperture of 30 cm combined with a relatively high-gradient field. The technique**** used in these Superconducting Multipole Triplets (SMT) coils aims to generate a very precise multipole fields, able to correct 2nd and 3rd order aberrations. We believe that this technique is applied, at this scale, for the first time in a heavy ion spectrometer of the nuclear physics domain. Detailed information of the progress of the qualification of the magnets and associated equipment, as well as the concept of the S3 spectrometer design will be presented.