A new ISOL rare isotope beam production facility, ARIEL, is being commissioned to triple the availability of radioactive ion beams for the ISAC experimental facilities at TRIUMF. Part of ARIEL is the new CANREB charge breeding facility that includes RFQ cooler, EBIS and Nier separator, and a high-resolution mass separator system (HRS). The HRS is designed to achieve a resolving power of 20,000 for a transmitted emittance of 3 µm with an energy spread of less than 0.5 eV for a beam energy up to 60 keV. The beam commissioning with stable ion beams was staged, using optical tunes developed for different mass resolving power: 5000, 10,000 and 20,000. Presently we are in the final development stage where we seek to reach the highest resolving power as per design, which requires correcting the high-order aberrations using our innovative and unique electrostatic multipole featuring an unconventional rectangular design. In this paper we are going to discuss issues encountered during the commissioning runs, and present recent results.

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.

The Electron Ion Collider is adopting a crabbing scheme of 25 mrad crossing angle. The local crab cavity system designed to kick the bunches in the first interaction region (IR) also introduces higher order multipoles com-ponents in electric field which affect the dynamic aperture. We have studied the strength of each multipole up to n = 4, or octupole, with respect to the main dipole field in different operating scenarios. Dynamic aperture study has continued with a fundamental crabbing system at 197 MHz and its second harmonic system at 394 MHz. A comparison of multipole effect for different phase ad-vance between the two crab cavity systems across the IP is shown in this paper. Method of decreasing the sextupole component is investigated as a result of the dynamic aper-ture requirement.

Fixed Field Accelerators are a candidate for future hadron cancer therapy facilities as their high repetition rate and large energy acceptance enables novel treatment modalities such as high dose rate FLASH. However, conventional dose delivery mechanisms are still necessary, requiring continuous beam delivery over 1--30s. This work is the first study of slow extraction from a scaling Fixed Field Accelerator, using the LhARA facility for baseline parameters. At a horizontal tune of 10/3, the intrinsic sextupole strength of the nonlinear FFA magnetic field is sufficient to excite the resonance, although extraction is better controlled using an additional excitation sextupole at a tune close to 8/3, with radiofrequency knock-out extraction. Including considerations of issues due to nonlinear fields and limitations required to keep the tune energy-independent, slow extraction from Fixed Field Accelerators is successfully demonstrated.

Insertion devices may be also very detrimental for the dynamic aperture of storage rings, since they introduce linear and higher order perturbations on the optics of synchrotrons. It is essential to study these effects to adjust the lattice to compensate for these terms when possible (high order multipole magnets are present in the lattice of the machine), or optimize the design of the IDs to minimize the higher order effects. We applied our analysis to SLS~2.0, the upgrade of the presently running Swiss Light Source (SLS) facility at Paul Scherrer Institut. In particular, we compared the results using an approach based on the calculation of the multipoles computed on the beam reference trajectory and on the kick map calculation.

Recent studies by Dejan Trbojevic have confirmed that Non-Scaling Fixed Field Accelerators (NS-FFAs) can have their tune dependence on momentum flattened by adding non-linear components to the magnet fields, although not necessarily for an unlimited momentum range. This paper presents such a cell suitable for the proposed 3-12MeV FETS-FFA proton R&D ring at RAL. The nonlinear magnetic field components are found automatically using an optimiser and settings covering a ring tune range of one unit in both planes independently are attainable. A fully configurable magnet with multiple windings across its horizontal aperture has been designed in 2D using Poisson, which can produce the required nonlinear fields without exceeding 5A/mm^2 current density.

The synchrotron SIS100 at FAIR, currently under construction in Darmstadt, Germany, will deliver slow extracted proton and ion beams up to 100 Tm employing resonant extraction. Its compact super-ferric dipole and quadrupole magnets allow fast ramping of magnetic field up to 4 T/s and 57 (T/m)/s, respectively. Recently, field errors has been measured for the dipole magnets and the first batch of quadrupole magnets. Higher order multipoles may interfere with resonant extraction, changing the geometry of the separatrix and conditions for resonant particles. The latter are affected most during their last turns and in the extraction channel owing to their large amplitudes, which amplify the effect of higher order multipoles. SIS100 comprises a set of corrector magnets up to octupole order, which can be used to compensate the impact of magnetic field errors. In this contribution, we report on the status of the slow extraction simulation studies including field errors. Furthermore, we present alternative working points for slow extraction, which are necessary to avoid the transition energy for some of beams required by the FAIR experiments.

Traditionally PIC solver compute electric field created by the beam as a mean field. The effect of particle collisions is normally neglected by the algorithm. In this proceeding we address how to include the collisions between the macro particles, and discuss the computational challenges and strategies to include the collisionallity in PIC solvers as particle-particle interaction. We present simulations that benchmark our understanding and analyse potential artifacts as energy conservation or other effects.

In Particle accelerators, commissioning of a complex beam line requires extensive use of computer models. When the as-built beam line cannot be exactly modeled by the simulation (due for example to mechanical errors or to the extensive usage of the non-linear focusing forces), the solution found in the simulations needs to be adjusted. Thus, it is often required to modify the settings by exploring different parameters ranges on the real accelerator. Given the high parameter space, this is a demanding task both in term of beam time and in term of required expertise. Furthermore, there is no guarantee to reach the optimal solution. This paper proposes a Reinforcement Learning approach to develop a model able to efficiently explore the parameter space of a beam line and iteratively move towards the optimal solution. The approach is first applied for the ADIGE Medium Resolution Mass Separator (MRMS) at INFN Legnaro National Laboratories (LNL), where the potentials of an electrostatic multipole must be correctly tuned to minimize the output beam emittance after the separation stage.

Fringe fields at the entrance and exit of multipole magnets can adversely affect the dynamics of particles in the beam, but there is also the possibility that fringe fields of the right form could be used to enhance the accelerator performance. Accelerator design work could benefit from efficient and realistic models of multipole fringe fields at an early stage in the design process. We explore novel techniques based upon analytical solutions of multipole fringe fields to produce magnets that satisfy specific requirements for the beam dynamics. Machine learning techniques are used in the design process currently being developed, to link properties of the beam dynamics to the magnet geometry in an efficient way.

While the design of the ALBA-II is in progress, it is required to assess the consequences of realistic imperfections such as alignment tolerances and magnetic errors. Compensation of insertion device induced optics variation has been studied, as well as the small impact on the emittance due the introduction of 3 T superbends. We demonstrate that non-linear optics is rather robust in the presence of realistic imperfections, rendering a ±6 mm dynamic aperture sufficient for off-axis injection and a large momentum acceptance that supplies more than 5 hour lifetime including errors. Moreover, studies in preceding low emittance light sources required simulating the full accelerator tuning, starting from the commissioning phase. To this end, the Simulated Commissioning (SC) toolbox has been used intensively. Specific set of tests have been developed to complement the SC simulations including lifetime and dynamical aperture calculations assuming a possible operation in full coupling.

Abstract A geometric control theory method is outlined & pre- sented to improve the on & off-momentum dynamic aper- ture for synchrotrons. And applied to the two lattice op- tions/solutions for BESSY III. A guideline is also provided for how to estimate the resulting performance for the “real lattice. The so-called tune confinement approach [32].

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.

The Rapid Cycling Synchrotron (RCS) of the Electron Ion Collider (EIC) is the injector of the Electron Storage Ring (ESR). The dynamic range of the RCS is from 0.4 GeV to 18 GeV. The RCS will use normal conducting dipoles, quadrupoles, and sextupoles. With errors to the main dipole field and misalignment to the elements included in the model, an orbit correction scheme has been developed. These magnet to magnet variations to the main field of the elements were studied as well as the effects of the multipole field errors. The impact of these errors and misalignments on the dynamic aperture will be presented.

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.

Superconducting dipoles with a strong curvature (radius smaller than 2 meters, for an aperture of about 100 mm and a length of 1-3 meters) are required for applications where compactness is key, such as the synchrotron and gantry for Carbon-ion therapy developed within the European program HITRIplus. Such magnets challenge several assumptions in the field description and put to the test the range of validity of beam optics codes. In particular, the equivalence that holds for the straight magnets between the transverse multipoles description obtained from the Fourier analysis (used for magnet design and measurements) and the Taylor expansion of the vertical field component along the horizontal axis (used in beam optics) is not valid any longer. A proper fringe field modelling also becomes important, due to the curved geometry and the aperture being large compared to the magnetic length. We explore the feasibility and the limits of modeling such magnets with optics elements (such as sector bends and multipoles), which allows parametric optics studies for optimization, field quality definition and fast long-term multi-pass tracking.

Magnetic Field Tools is an open source library being developed by the Insertion Devices and Magnets group at the ESRF. It is dedicated to the analysis of static magnetic field values obtained from simulations and measurements. Magnetic field models such as 2D and 3D multipoles in various geometries, as well as boundary element models, can be built from sets of field samples. The library was designed in order to be easily extendable to other types of field models. It is implemented in C++ and a Python binding is available. Application to undulator magnets, 3D multipole fringe fields and solenoids will be presented.

The proposed PETRA IV electron storage ring, that will replace DESY’s flagship synchrotron light source PETRA III, will feature a horizontal emittance as low as 20 pm∙rad. It is based on a hybrid six-bend achromat lattice. In addition to the storage ring PETRA IV, DESY IV booster synchrotron and the corresponding transfer lines will be renewed. About 4000 magnets will be manufac-tured. Some of the magnets have demanding specifica-tions due to high magnetic field in the poles. High pack-ing density of lattice elements implies short distances between the magnets and results in magnetic cross-talk. This contribution presents the details of the design and prototyping of the storage ring electromagnets.

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.

he Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBL) is going through an upgrade (ALS-U) where the ALS triple-bend achromat will be replaced by a nine-bend achromat storage ring (SR) with an on-axis injection using beam swapping from a triple-bend achromat accumulator ring (AR). About 700 magnets will be used for the ALS-U accelerator systems. The paper gives an overview of the stretched wire and rotating coil systems used for the magnetic measurements of the ALS-U magnets. We are also describing the fiducialization process, i.e. the mechanical and magnetic alignment of the magnets.

A 4th generation storage ring based light source is being developed in Korea since 2021. It features < 100 pm rad emittance, about 800 m circumference, 4 GeV e-beam energy, full energy booster injection, and more than 40 beamlines which includes more than 24 insertion device (ID) beamlines. This machine requires about ~1300 magnets including dipole, longitudinal gradient dipole, transverse gradient dipole, sextupoles, and correctors. In this report, the current status and prototyping status of some key magnets are presented. Particularly, impact of the end chamfering of the quadrupole magnet on the integrated multipoles are analyzed and optimum and (hopefully universal) chamfering profile is suggested.

As multipurpose synchrotron radiation facilities, the Korea-4GSR is being promoted in Korea from July 2021 to the end of 2027. The construction project includes linac, 4 GeV booster, and storage ring. The circumference of the storage ring is about 800 meters, the beam emittance is 58 pm.rad, and there are more than 40 beamlines with 28 superperiods. A large number of electromagnets are used in these facilities. This presentation describes the design of the dipole quadrupole (DQ) magnets used in the storage ring. The DQ magnets are basically offsetted standard quadrupoles for design simplicity. The poles are optimized for minimum harmonic content and maxi-mum B’ with tapering. All DQ magnets should have trim coils for dipole component that will be used to keep the dipole field while quadrupole field changes.

The new fourth-generation synchrotron radiation source PETRA IV at DESY (Hamburg) will use a fast orbit feedback system to meet stringent orbit stability requirements. To this end, hundreds of fast orbit corrector magnets will be installed to minimize orbit distortions from external sources. These magnets are operated at high frequencies, creating strong eddy currents that result in Joule losses and a time delay between the applied voltage and the aperture field. User experiments impose stringent requirements on beam operation to preserve the point of the radiation source. To meet the demanding feedback requirements, finite element simulations are needed to understand the characteristics of the fast corrector magnet and its environment. However, due to the low skin depths at high frequencies and the laminated structure of the magnets' yoke, conducting finite element simulations of the fast correctors is computationally very demanding. Therefore, we homogenize the laminated yoke which drastically reduces the computational effort but still captures the eddy current effects accurately. The homogenization technique reduces simulation times from several hours to just a few minutes, allowing us to conduct extensive studies of the power losses, the field quality, and the integrated transfer functions of the magnets.

The Hefei Advanced Light Facility (HALF) is a future soft X-ray diffraction-limited storage ring at National Synchrotron Radiation Laboratory (NSRL), which aims to decrease the horizontal emittance to improve the brilliance and coherence of the soft X-ray beams. The lattice of the ring depends on the use of many short and high field multipole magnets, dipole-quadrupole magnets with high gradients (DQ) and dipoles with longitudinal gradients (DL). Due to the high gradient of DQs, it is a better choice to obtain the ideal field with an offset quadrupole design. The longitudinal gradient dipoles are electromagnets with different gaps for the requirement of the field adjustment. The design of all multipole magnets relies on a new optimization method based on NSGAII and the good results have been achieved. The design has been completed and the prototype of DL2 is under construction.

Wuhan Advanced Light Source (WALS) is a proposed 4th generation light source, which accelerators include a 1.5 GeV Linac, 1.5 GeV storage ring and one beam transport line. The ring lattice consists of 8 identical units of 7BA. In each unit, there are 7 longitudinal gradient dipoles with transversal gradients, 10 quadrupoles, 6 sextupoles, 4 anti-bending gradient dipoles. Moreover, a combined dipole which field arrives at 3.67T is located at the middle of unit, which is used for obtaining hard-X ray. In this paper, the status of WALS ring magnets will be presented and the key technical issues for the magnet performance, such as the method of permanent magnets, pole faces optimizations with NSGA-II methods, structures and assembly will be thoroughly discussed.

The MQXFB magnets are superconducting quadrupoles with nominal peak field on the conductor of 11.3 T. With their magnetic length of 7.2 m, they stand as the longest Nb3Sn accelerator magnets designed and manufactured up to now. Together with the companion MQXFA 4.2 m long units, built by the US Accelerator Research Program, they are at the heart of HL-LHC, as they shall replace the inner triplet quadrupoles at either side of the ATLAS and CMS interaction regions of the LHC. This technology has benefited from many years of development, and this specific design was validated with successful short models (MQXFS, 1.2 m long). More recently, several MQXFA magnets were shown to satisfy HL-LHC requirements. In this paper, we report on the cold test results of four MQXFB magnets, focusing on performance, training, behavior after thermal and powering cycles, and field quality. We then provide an update of the overall status, including ongoing verifications of design changes at the level of the coil fabrication.

Elettra 2.0 is the Project finalized to upgrade the Storage Ring (SR) and part of the beamlines (BLs) of Elettra. The machine optics requires a significant number of magnets and additional coils to energize individually. More than 1200 DC power converters (PCs) are foreseen. A synergic design of the magnets and the associated PCs led to a great standardization: four current ranges (300 A, 100 A, 20 A, 5 A) and, consequently only four different types of PCs. While the 20 V/300 A PCs (72 units) have been ordered on the market with a “built-to-specification” procedure, the 15 V/100 A and the 10 V/20 A units (together account to about 1000 units) are an in-house design and their procurement will follow a “built-to-print” procedure. The 15 V/5 A type (not less than 250 units) is still under design and will follow the same approach of the 100 A and 20 A ones. This paper gives an overview on the magnet power converter system, the results of the tests on the prototypes and the installation strategy.

The Iranian Light Source Facility (ILSF) is in the detailed design phase. It will operate at 3 GeV and 400 mA with an ultra-low horizontal emittance of 0.27 nm. rad. The main storage ring combined dipole magnet has a 0.56 T magnetic field and a -7 T/m gradient. It can serve as a soft X-ray source, and there are several ways to achieve hard X-rays; one is to use a high-field dipole. It is designed with a permanent magnet and consists of three parts; a high field part that provides a 3 T magnetic field and two low field parts on either side of the high field one. The basic design of the super-bend dipole magnet is presented here.

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.

A design study is currently underway at the University of Melbourne for a large energy acceptance beamline to enable future hadron therapy modalities. As part of the TURBO project, a beam delivery system demonstrator is being developed for a DC Pelletron accelerator, which will provide 3 MeV H+ beams. Fixed Field Accelerator optics will be used to maximise momentum acceptance, with dispersion minimised at both ends of the transport line. This project aims to be the first `closed dispersion arc' with fixed fields ever constructed. As part of the design process, the input beam phase space from the Pelletron has been characterised. Our results show that the Pelletron beam can be injected into the novel transport line successfully, and Zgoubi simulations show that near-zero dispersion at each end will be achievable. This is supplemented by error studies and magnet investigations, demonstrating that beam transport can be achieved under realistic circumstances. This initial study establishes the feasibility of this beamline design and work is continuing toward further optimisation for implementation.

Superconducting curved magnets are able to reduce accelerator footprints by producing strong fields (>3T) for applications such as carbon ion therapy, however the effect of strongly curved magnetic multipoles and fringe fields on accelerator beam dynamics is not fully understood. This is especially important in compact synchrotrons, where fringe fields can significantly affect beam quality and long-term beam stability. To establish tolerances on these higher order harmonic errors, an electromagnetic model of a superconducting, strongly curved canted-cosine-theta (CCT) combined-function dipole is analysed. The CCT magnet is studied as a potential option for the main dipole of a 27m circumference carbon ion therapy synchrotron within the Next Ion Medical Machine Study (NIMMS) at CERN and the European project HITRIplus. Curved magnetic multipoles are modelled in MAD-X and PTC; results are presented and compared with particle tracking through the magnet’s 3D fieldmap in Zgoubi for additional investigation of non-linear effects. Preliminary assessment of the performance of the synchrotron subject to the tolerances on the harmonic errors is given with discussion for the suitability of the synchrotron for clinical applications.