Search

Electron cooling as a method of creating intense ion beams has a practical upper limit when it comes to the peak phase space density of ion beams which can be achieved in practice. We describe a new experiment to study electron cooling of 2.5 MeV protons at the intensity limit using the Integrable Optics Test Accelerator (IOTA), which is a storage ring dedicated to beam physics research at Fermilab. This system will enable the study of magnetized electron cooling of a proton beam with transverse incoherent tune shifts approaching -0.5 due to the presence of intense space-charge forces. We present an overview of the hardware design, simulations and specific experiments planned for this project., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Resonant slow extraction from synchrotrons aims at providing constant intensity spills over timescales much longer than the revolution period of the machine. However, the extracted intensity is undesirably modulated by noise on the machine’s power converters with a frequency range of between 50 Hz and a few kHz. The impact of power converter noise can be suppressed by exploiting a Radio Frequency (RF) technique known as empty bucket channelling, which increases the speed at which particles cross the tune resonance boundary. In this contribution the implementation of empty bucket channelling in the CERN Proton Synchrotron (PS) is described via simulation and measurement. The technique was tested with both a resonant RF cavity and an inductive Finemet cavity, which can produce non-sinusoidal waveforms, to significantly reduce the low frequency noise observed on the extracted spill., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and will deliver 10 low-beta cryomodules as In-Kind Contribution to the PIP-II project, with cavities supplied by LASA-INFN and power couplers and tuning systems supplied by Fermilab. This paper presents the CEA scope of work that includes the design, manufacturing, assembly and tests of the cryomodules and the upgrade of the existing infrastructures to the PIP-II requirements., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

At J-PARC main ring (MR), the two fast extracting beamlines to the neutrino facility and to the abort dump have a symmetrical layout of 6 septum magnets each, a total of 12. Since there are many magnets, it is necessary to be careful about failure. It is important to consider how to continue beam supply even if one of the septum mag-nets is missing. From July 2021, upgrade works of the FX septum magnets commenced with an aim of increasing the beam power of MR to 1.3 MW from 500 kW. We simulated the beam extraction without one of the septum magnets under the conditions of the new geometry of septum magnets and the new aperture. We found that the beam can be extracted by increasing the current of the surrounding septum magnets and compensating for the output., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The intensity frontier has called for new initiatives in hadron accelerator design in order to accommodate space charge dominated beams. Octupoles are often used to damp beam instabilities caused by space charge, however the insertion of octupole magnets leads to a nonintegrable lattice which reduces the area of stable particle motion. One proposed solution is Quasi-Integrable optics (QIO), where the octupoles are inserted between sections of a specific lattice insertion called a T-insert. An octupole with a strength that scales as 1/beta³(s) is applied in the drift region, where the horizontal and vertical beta functions are equal, to create a time independent octupole field. This leads to a lattice with a time-independent Hamiltonian which is robust to small perturbations. IBEX is a Paul trap which allows the transverse dynamics of a collection of trapped particles to be studied, mimicking the propagation through multiple quadrupole lattice periods, whilst remaining stationary in the laboratory frame. In order to test QIO at the IBEX experiment, it has recently undergone an upgrade to allow for the creation of octupole fields. We present our design of the IBEX experiment upgrade along with simulation results of our proposed experiment to test QIO with space charge., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The injection process in the LHC gives a non-negligible contribution to the turnaround time between two consecutive physics fills. Mainly due to orbit drifts in the SPS, the steering of the SPS-to-LHC transfer lines (TL) had to be regularly performed in view of minimising injection oscillations and losses, which otherwise would trigger beam dumps. Moreover, for machine protection purposes, a maximum of twelve bunches had to be injected after any TL steering to validate the actual applied corrections. This implied at several occasions the need to interrupt a fill to steer the lines and introduced a further delay between fills. Studies were performed to evaluate the option of pre-calculating the required TL corrections based on SPS orbit measurements during the LHC magnet ramp down and the reconstruction of the beam position and angle at the SPS extraction point., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Cyclotrons are the oldest type of circular accelerators, with many applications, design of the majority of cyclotrons nowadays follow has become a standard for most of developers, and there is a clear trend for switching towards superconducting magnets to increase the magnet field level and descrease the size and weight. A new approach, described in this paper allowed the author to design a lineup of cyclotrons from 15 to 230 MeV as compact and power efficient as superconducting cyclotrons, but using copper coil., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

ELENA is a small synchrotron ring that decelerates antiprotons down to a kinetic energy of 100 keV. With an experimental complex capable of housing up to 9 different experiments operating simultaneously, the transfer line design needed to be highly flexible. The low energy of the beam transported allowed the exploitation of electrostatic devices instead of magnets, to simplify design, production and operation. This contribution presents the systematic characterisation of the beam optics at the different experimental handover locations during beam commissioning using H⁻ ions from an external source, as well as the performance of the lines in operation with antiprotons. Finally, the effect of stray fields created by the experimental setup will be presented and compared with the first measurements., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand, 12 Jun 2022 - 17 Jun 2022; JACoW Publishing, Geneva, Switzerland 4 pages (2022). doi:10.18429/JACOW-IPAC2022-MOPOST016, Due to the decommissioning of several reactors, only about half of the neutrons will be available for research in Europe in the next decade despite the commissioning of the ESS. High-Current Accelerator-driven Neutron Sources (HiCANS) could fill this gap. The High Brilliance Neutron Source (HBS) currently under development at Forschungszentrum Jülich is scalable in terms of beam energy and power due to its modular design. The driver linac will accelerate a 100 mA proton beam to 70 MeV. The linac is operated with a beam duty cycle of up to 13.6 % (15.3 % RF duty cycle) and can simultaneously deliver three pulse lengths (208 µs, 833 µs and 2 ms) for three neutron target stations. In order to minimize the development effort and the technological risk, state-of-the-art technology of the MYRRHA injector is used. The HBS linac consists of a front end (ECR source, LEBT, 2.5 MeV double RFQ) and a CH-DTL section with 44 room temperature CH-cavities. All RF structures are operated at 176.1 MHz and are designed for high duty cycle. Solid-state amplifiers up to 500 kW are used as RF drivers. Due to the beam current and the high average beam power of up to 952 kW, particular attention is paid to beam dynamics. In order to minimize beam losses, a quasi-periodic lattice with constant negative phase is used. This paper describes the conceptual design and the challenges of a modern high-power and high-current proton accelerator with high reliability and availability., Published by JACoW Publishing, Geneva, Switzerland

The Bonn Isochronous Cyclotron provides proton, deuteron, alpha particle and other light ion beams with a charge-to-mass ratio Q/A of ’ 1/2 and kinetic energies ranging from 7 to 14 MeV per nucleon. At a novel irradiation site, a 14 MeV proton beam with a diameter of a few mm is utilized to homogeneously irradiate silicon detectors, so-called devices under test (DUTs), to perform radiation hardness studies. Homogeneous irradiation is achieved by moving the DUT through the beam in a row-wise scan pattern with constant velocity and a row separation smaller than the beam diameter. During the irradiation procedure, the beam parameters are continuously measured non-destructively using a calibrated, secondary electron emission-based beam monitor, installed at the exit window of the beamline. The diagnostics and the irradiation procedure ensure a homogeneous irradiation with a proton fluence error of smaller than 2 %. In this work, an overview of the accelerator facility is given and the irradiation site with its beam diagnostics is presented in detail., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC) will accelerate protons and heavy ions up to a proton energy of 275 GeV and an Au⁺⁷⁹ 110 GeV/u to collide with electrons of energies up to 18 GeV. To accomplish the acceleration process, the hadrons are pre-accelerated in the Alternating Gradient Synchrotron (AGS), extracted, and transferred to HSR for injection. The planned area for injection is the current Relativistic Heavy Ion Collider (RHIC) 4 o’clock straight section. To inject hadrons, a series of modifications must be made to the existing RHIC 4 o’clock straight section to accommodate for the 20 new ~18 ns injection kickers and a new injection septum, while providing sufficient space and proper beam conditions for polarimetry equipment. These modifications will be discussed in this paper., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) is the world’s largest and most powerful particle accelerator colliding beams of protons and lead ions at energies up to 7 TeV and 2.76 TeV, respectively. ALICE is one of the detector experiments optimised for heavy-ion collisions. A fixed-target experiment in ALICE is considered to collide a portion of the beam halo, split using a bent crystal, with an internal target placed a few meters upstream of the detector. Fixed-target collisions offer many physics opportunities related to hadronic matter and the quark-gluon plasma to extend the research potential of the CERN accelerator complex. Production of physics events depends on the particle flux on target. The machine layout for the fixed-target experiment is being developed to provide a flux of particles on a target high enough to exploit the full capabilities of the ALICE detector acquisition system. In this paper, we discuss a method of increasing the system’s performance by applying a local modification of optics to set the crystal at the optimal betatron phase., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Electron-Ion Collider (EIC) Hadron Storage Ring (HSR) will be composed of the current Relativistic Heavy Ion Collider (RHIC) yellow ring sextants with the exception of the 1 o’clock and the 11 o’clock arc. These two arcs use the existing blue ring inner (1 o’clock) and outer (11 o’clock) magnetic lattice for 275 GeV proton operation. The inner yellow 11 o’clock arc is used for 41 GeV energy operation. A switching magnet must be used to guide the hadron beam from the low and high energy arc respectively into the shared arc. This report provides the necessary lattice configuration, magnetic fields, and optics for the 10 o’clock utility straight section (USS) switchyard for both high and low energy configuration while providing the necessary space allocations and beam specifications for accelerator systems such as an additional radiofrequency cavity and beam dump., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

After the implementation of major upgrades as part of the LHC Injector Upgrade Project (LIU), the Super Proton Synchrotron (SPS) delivers high intensity bunch trains with 25 ns bunch spacing to the Large Hadron Collider (LHC) at CERN. These beams are exposed to several collective effects in the SPS, such as beam coupling impedance, space charge and electron cloud, leading to relatively large bunch-by-bunch coherent and incoherent tune shifts. Tune correction to the nominal values at injection is crucial to ensure beam stability and good beam transmission. During the beam commissioning of the SPS, measurements of the bunch-by-bunch coherent tune shifts have been conducted under different beam conditions, together with appropriate corrections of the average tunes at each injection. In this paper, we describe the methodology that has been developed to acquire bunch-by-bunch position data and to perform online computations of the coherent tune spectra of each bunch using refined Fourier transform analysis. The experimental data are compared to multiparticle tracking simulations using the SPS impedance model, in view of developing an accurate model for tune correction in the SPS., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The study of beam dynamics in accelerators featuring main magnets with complex geometries such as Fixed Field Accelerators (FFAs) requires simulation codes allowing step-by-step particle tracking in complex magnetic fields, such as the Zgoubi ray-tracing code. To facilitate the use of Zgoubi and to allow readily processing the resulting tracking data, we developed a modern Python 3 interface, Zgoubidoo, using Zgoubi in the backend. In this work, the key features of Zgoubidoo are illustrated by detailing the main steps to obtain a non-scaling FFA accelerator from a scaling design. The results obtained are in excellent agreement with prior results, including the tune computation and orbit shifts. These results are enhanced by Zgoubidoo beam dynamics analysis and visualization tools, including the placement of lattice elements in a global coordinate system and the computation of linear step-by-step optics. The validation of Zgoubidoo on conventional scaling and non-scaling FFA designs paves the way for future uses in innovative FFA design studies., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) working group at CERN is investigating the feasibility of delivering high energy ion beams to the CHARM facility for the study of radiation effects to electronics components engineered to operate in harsh radiation environments, such as space or high-energy accelerators. The Proton Synchrotron has the potential of delivering the required high energy and high-Z (in this case, Pb) ions for radiation tests over the relevant range of Linear Energy Transfer of ~ 10 - 40 MeV cm²/mg with a > 1 mm penetration depth in silicon, specifically for single event effect tests. This contribution summarises the working group’s progress in demonstrating the feasibility of variable energy slow extraction and over a wide range of intensities. The results of a dedicated 6 GeV/u Pb ion beam test are reported to understand the performance limitations of the beam instrumentation systems needed to characterise the beam in CHARM., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The ECR ion sources are widely used to produce high intensities of highly charged positive ions*. To increase their performance further, several techniques are employed. The addition of a lighter gas into the main plasma (so-called gas mixing) shows a substantial effect on the charge state distribution of highly charged ions. Although many theoretical models were used to explain this gas mixing effect, yet it is not fully understood. The low energy ion beam facility (LEIBF) at Inter-University Accelerator Centre (IUAC), New Delhi, India, which comprises a 10 GHz all-permanent magnet NANOGAN ECR source placed on a high voltage platform (400kV) has been used to develop several plasmas for the physical understanding of ions production and their confinement in a strong magnetic field**. Further, the LEIBF allows us to extract ion beams from the plasma in the energy range of a few keV to tens of MeV for novel ion-matter interaction experiments. In this paper, the charge state distribution studies (relevant to gas mixing effect) of various atomic species at optimized ion source tuning parameters along with some interesting results on materials synthesis/modification using ion beams is presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

RIKEN RI Beam Factory (RIBF), providing the world’s most intense heavy-ion beams more than 345 AMeV, is a leading facility for generating in-flight RI beams. RIBF has been steadily developing its performance after since 2006. In particular, the beam intensity of uranium beams, which is important to produce in-flight fission RI beams, was drastically increased by a factor of 240 compared to 2008. For further intensity upgrade of the uranium beams, the total charge stripping efficiency less than 5% of two strippers, He gas and rotating graphite sheet disk strippers, is a serious bottleneck. A new acceleration scheme with charge stripper rings (CSRs) as a cost-effective way to enhance the charge stripping efficiency has been proposed. The CSR recycles beams other than the selected charge state that was previously dumped. These beams are orbited in the CSR while suppressing emittance growth, and then re-enter the stripper. The CSR is being studied as a future plan, aiming at a 10-fold increase in the intensity of the uranium beams. The present status and the future plan with the CSR at RIBF will be presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Rare isotope Accelerator Complex for ON-line experiments (RAON) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from hydrogen (proton) to uranium. Protons and uranium ions are accelerated up to 600 MeV and 200 MeV/u respectively. It can provide various rare isotope beams which are produced by isotope separator on-line system. The RAON injector was successfully commissioned in 2021 to study the initial beam parameters from the main technical systems, such as the ECR ion source and RFQ, and to find the optimized LEBT and MEBT setpoints and matching conditions. In this paper, we present the current commissioning status of the RAON injector in preparation for the upcoming SCL3 beam commissioning., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Following the successful completion of the second long shutdown (LS2), the Large Hadron Collider (LHC) is preparing for its final operational run before the majority of the High Luminosity Upgrade (HL-LHC) will be installed during the third Long Shutdown starting in 2026. The HL-LHC upgrade will enable a further tenfold increase in integrated luminosity delivered to the ATLAS and CMS experiments, starting by an upgrade of the machine protection, collimation and shielding systems in LS2, and followed by the deployment of novel key technologies, including Nb₃Sn based insertion region magnets, cold powering by MgB₂ superconducting links and integration of Nb crab-cavities to compensate the effects of a larger crossing angle. After a period of intensive R and prototyping, the project is now entering the phase of industrialization and series production for all main components. In this contribution, we provide an overview of the project status and plans for deployment and performance ramp-up. Progress on the validation of key technologies, status of prototypes and series production as well as the final integration studies for the HL equipment are summarized. These are accompanied by the imminent completion of major civil engineering work and the start of infrastructure installations. Initial operational experience will be gained at the Inner Triplet (IT) String, presently in assembly at CERN’s Superconducting Magnet Test Facility, which will enable a fully integrated test of the main magnets, powering, and protection systems in the actual HL-LHC insertion configuration., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

At GSI a prototype electron lens for space charge (SC) compensation is currently being designed and main components as the RF-modulated electron gun are already under commissioning. The goal of this project is the (partial) compensation of SC forces within the ion beam by an overlapping electron beam. This may help to increase the intensity of primary beams, especially in the FAIR facility and potentially all large synchrotrons operated at the SC limit. For an effective SC compensation, the generated electron beam needs to follow the transverse and longitudinal beam profile of the ion bunch structure. The requirements are maximum currents of 10 A and grid modulation to cover a broad frequency range from 400 kHz to 1 MHz. The RF-modulated electron gun was designed and manufactured in the scope of the ARIES collaboration and is currently being tested at the E-Lens Lab of Goethe University Frankfurt. A dedicated test bench was built for commissioning of the major e-lens components and diagnostics. In this contribution the overall set-up will be presented putting special emphasis on the beam dynamics and collector design as well as as well as simulation results of the electron gun., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.4 m Ladder-RFQ*. The Ladder-RFQ features a very constant voltage along the axis as well as low dipole modes. The unmodulated prototype accepted 3 times the operating power of which is needed in operation** corresponding to a Kilpatrick factor of 3.1 with a pulse length of 200 µs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project***. This particular high frequency for a 4-ROD-RFQ creates difficulties, which triggered the development of a Ladder-RFQ with its high symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is very well suited for that frequency. For the applied cooling concept, the Ladder-RFQ can be driven up to a duty factor of 10%. Manufacturing has been completed in September 2018. The final flatness frequency tuning as well as the final assembly have been completed. We present the final RF measurements and assembly steps getting the Ladder-RFQ ready for shipment and high power RF test prior to assembly., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The reaccelerator ReA is a state-of-the-art super-conducting linac for reaccelerating rare isotope beams produced via inflight fragmentation or fission and subse-quent beam stopping. ReA was subject of an upgrade that increased its final beam energy from 3 MeV/u to 6 MeV/u for ions with charge over mass equal to 1/4. The upgrade included a new room-temperature rebuncher after the first section of acceleration, a new β = 0.085 QWR cryomodule and two new beamlines in a new ex-perimental vault. During commissioning, beams were accelerated with near 100 percent transport efficiency through the linac and delivered through beam transport lines. Measured beam characteristics match those calcu-lated. Following commissioning, stable and long living rare isotope beams from a Batch Mode Ion Source (BMIS) were accelerated and delivered to experiments. This con-tribution will briefly describe the upgrade, and results from beam commissioning and beam delivery for experi-ments., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Rapid advances in superconducting magnets and related accelerator technology opens many unexplored possibilities for future synchrotron designs. We present an efficient method to probe the feasible parameter space of synchrotron lattice configurations. Using this method, we can converge on a suite of optimal solutions with multiple optimisation objectives. It is a general method that can be adapted to other lattice design problems with different constraints or optimisation objectives. In this method, we tackle the lattice design problem using a multi-objective genetic algorithm. The problem is encoded by representing the components of each lattice as columns of a matrix. This new method is an improvement over the neural network based approach* in terms of computational resources. We evaluate the performance and limitations of this new method with benchmark results., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

In this contribution we provide a summary of the LHC hardware commissioning campaign following the second CERN Long Shutdown (LS2), initially targeting the nominal LHC energy of 7 TeV. A summary of the test procedures and tools used for testing the LHC superconducting circuits is given, together with statistics on the successful test execution. The paper then focuses on the experience and observations during the main dipole training campaign, describing the encountered problems, the related analysis and mitigation measures, ultimately leading to the decision to reduce the energy target to 6.8 TeV. The re-commissioning of two powering sectors, following the identified problems, is discussed in detail. The paper concludes with an outlook to the future hardware commissioning campaigns, discussing the lessons learnt and possible strategies moving forward., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

To provide HL-LHC performance, the CERN LHC injector chain underwent a major upgrade during an almost 2-year-long shutdown. In the first half of 2021 the injectors were gradually re-started with the aim to reach at least pre-shutdown parameters for LHC as well as for fixed target beams. The strategy of the commissioning across the complex, a summary of the many challenges and finally the achievements will be presented. Several lessons were learned and have been integrated to define the strategy for the performance ramp-up over the coming years. Remaining limitations and prospects for LHC beam parameters at the exit of the LHC injector chain in the years to come will be discussed. Finally, the emerging need for improved operability of the CERN complex will be addressed, with a description of the first efforts to meet the availability and flexibility requirements of the HL-LHC era while at the same time maximizing fixed target physics output., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The design of the Electron-Ion Collider (EIC) Hadron Storage Ring (HSR) calls for using parts of both of the Relativistic Heavy Ion Collider (RHIC) Blue and Yellow beamlines. With the HSR having to circulate low (41 GeV) and high (100+ GeV) energy hadron beams while matching the time of flight in the Electron Storage Ring (ESR), it becomes necessary for the ring lattice to switch from an outer arc to an inner arc in order to accommodate for the change in circumference. To do so, a switchyard is planned for installation in the HSR straight section at 12 o’clock with the other switchyard being placed in the straight section immediately downstream, 10 o’clock. The 12 o’clock straight section is simultaneously dedicated to the EIC 2-stage collimation system. The following reviews the layout constraints in the12 o’clock straight section that come with installing such a switchyard, along with the implications on the linear optics for that straight section at all HSR rigidities. The space allocation, twiss parameters and the mechanical requirements of the HSR betatron collimators that will be installed in this section are also discussed., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

We discuss design considerations for a circular ion trap based on electromagnetic and particle beam simulations. This is a circular radiofrequency quadrupole (rfq) being designed for quantum information applications. The circular rfq should have good electromagnetic properties to accumulate and store the beam for prolonged times, while providing apertures for laser cooling and lower voltage electrodes to provide control over the beam. We use the electromagnetic and particle-in-cell software VSim, which uses finite difference time-domain and particle-in-cell methods, together with high performance computing tools., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The CERN LHC injector chain underwent a major upgrade during the Long Shutdown 2 (LS2) in the framework of the LHC Injectors Upgrade (LIU) project. After 2 years of installation work, the Proton Synchrotron (PS) was restarted in 2021 with the goal to achieve pre-LS2 beam quality by the end of 2021. This contribution details the main beam commissioning milestones, encountered difficulties and lessons learned. The status of the fixed-target and LHC beams will be given and improvements in terms of performance, controls and tools described., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The GSI Universal Linear Accelerator UNILAC and the synchrotron SIS18 will serve as injector for the upcoming FAIR-facility. The UNILAC-High Current Injector will be improved and modernized until FAIR is commissioned and the Alvarez poststripper accelerator is replaced. The reference heavy ion for future FAIR-operation is uranium, with highest intensity requirements. To re-establish uranium beam operation and to improve high current beam operation, different subjects have been explored in dedicated machine investigation campaigns. After a beam line modification in 2017 the RFQ-performance had deteriorated significantly; new rods have been installed and the RF-working point has been redefined. Also the Superlens-performance had become unsatisfactory; improved with a modified RF-coupler. With a pulsed hydrogen gas stripper target the uranium beam stripping efficiency could be increased by 65%. Various work has already been carried out to establish this stripper device in routine operation. With medium heavy ion beams a very high beam brilliance at the end of transfer line to SIS18 was achieved. Results of the measurement campaigns and the UNILAC upgrade activities will be presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Accelerators Validating Antimatter physics (AVA) project has enabled an interdisciplinary and cross-sector R program on low energy antimatter research. The network comprises 13 universities, 9 national and inter-national research centers and 13 partners from industry. Between 2016 and 2021, AVA has successfully trained 16 early-stage researchers that were based at universities, research centers and companies across Europe where they carried out cutting edge research into low energy antimat-ter physics and related technologies. This contribution presents several research highlights that originated within or on the basis of AVA: Results from studies into carbon nano-tubes as field emitters for cold electron beams with supe-rior beam quality, the design of a low energy negative ion injection beamline for experiments with antiprotonic atoms, and studies into realistic simulations of antiproton deceleration in foil degraders., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The J-PARC Main Ring (MR) is a high intensity proton accelerator and delivers 30 GeV proton beams for the long-base line neutrino experiment and the hadron experiments. At present, the beam intensity supplied to the neutrino experiment reached 520 kW with a cycle time of 2.48 s. Toward the design beam power of 750 kW and future goal of 1.3 MW, we chose shortening the MR operation cycle. Accelerating time is shortened in order to shorten the cycle, so a high accelerating voltage is required. Therefore, it is necessary to upgrade the RF systems. This RF upgrade expands the current nine RF systems to a total of thirteen. We are planning to fabricate four RF power sources and add four additional cavities that are recombined with existing cavities. The present status and upgrade plan of the MR RF systems are reported., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

For a system with the ion beam co-propagating with the electron beam, such as a traditional electron cooler or a Coherent electron Cooler (CeC), the recombination rate is an important observable for matching the energy of the electrons with the ions. In this work, we have developed the analytical expressions to investigate how the recombination rate depends on the energy difference of the two beams, with the influences from the transverse motions of the particles being considered. The analytical results are then used to analyze the measured recombination data collected during the CeC experiment in run 21 and run 22., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The isochronous optics of the ESR is a unique ion-optical setting in which the particles within a finite momentum acceptance circulate at constant frequency. It is used for direct mass measurements of short-lived exotic nuclei by a Time-of-Flight method. Besides the mass spectrometry, the isochronous ESR has been used as an instrument for the search of short lived isomers stored in the ring, which was performed in 2021 for the first time. Introduction to the isochronous mode of the ESR, comparison with a standard operational mode, recent machine experiments will be presented here. Possible improvements of the isochronous optics at the ESR and perspectives of the isochronous mode at CR, FAIR will be outlined., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

In December 2020 the newly commissioned LINAC4 started delivering beam for the CERN proton accelerator chain, replacing the old LINAC2. LINAC4 is a 352 MHz normal conducting linac, providing a beam of negative hydrogen ions at 160 MeV that are converted into protons at injection into the PS Booster synchrotron. In this paper we report on the achieved beam performance, availability, reproducibility and other operational aspects of LINAC4 during its first fully operational year. We also present the machine developments performed and the plans for future improvements., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The negative ion source development has reached performances very close to those required by the ITER project; see for example the test facility ELISE results*. A main residual problem seems to be the great amount of co-extracted electrons in the top part of the source. The introduction of a magnetic filter to remove the electrons from the extraction zone of the source causes ExB particle drifts (or shifts) which move both ions and electrons towards the top (or bottom depending on the B direction); in the top part the electron concentration and extracted current increase and that limits the extracted ion amount. In this contribution, as a possible solution, the application of a Planar Ion Funnel (PIF) extraction electric field configuration** on the source exit is proposed. The electric field line shape of PIF configuration, not only should break the perpendicularity between the magnetic filter B and the extraction electric field E in such a way to prevents the ExB particle drifts, but also should give a more efficient field shape for the H-/D- extraction. Preliminary simulations of D- and e⁻ trajectories are presented to confirm the efficiency of the PIF system., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

We aim to supply a high-power proton beam of 1.3 MW to the neutrino facility from J-PARC Main Ring (MR) by shortening the repetition cycle to 1.16 s from 2.48 s and increasing the number of particles by 30%. The six sep-tum magnets for fast extraction (FX) need to be replaced to reduce the heat that is generated as a result of shorten-ing the repetition cycle. The replacement of the septum magnets began in July 2021 and was completed at the end of May 2022. The beam commissioning starts in June 2022. We report the details of the replacement work and operation test of the new septum magnets. We found a defect in the magnetic coil of the septum (SM32) in August 2021. We decided to postpone its installation to around August 2022 and produce new magnet coils for the SM32. The beam extraction in June 2022 will be per-formed using a temporary vacuum duct instead of the SM32 magnet, and the extraction beam orbit will be maintained by increasing the magnetic field of the other five septum magnets., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

To prepare for polarized helion collisions at the Electron Ion Collider (EIC), polarization transmission at the injectors for the Hadron Storage Ring must be studied and optimized. To this effect, an AC dipole has been installed in the AGS Booster to maximize polarization transmission of helions through several intrinsic resonances. This installation also allows polarized protons to be extracted at higher energy without polarization loss. By increasing the proton extraction energy from $Gγ$ = 4.5 to $Gγ$ = 7.5, protons will cross the $Gγ$ = 0 + ν_{y}$ and $Gγ = 12 - ν_{y}$ depolarizing vertical intrinsic resonances, the $Gγ$ = 5, 6, and 7 imperfection resonances in addition to the $Gγ$ = 3, 4 that are crossed in the present configuration, and be injected into the AGS at a higher rigidity. By simulation, it is determined that there is sufficient strength of the AC dipole to fully flip the spin spin through each of the intrinsic resonances, and there is sufficient corrector current to preserve polarization through the three additional imperfection resonances. The higher injection rigidity facilitates the horizontal and vertical tunes being placed inside the AGS spin-tune gap at injection due to a substantial improvement on the AGS admittance at injection., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

We present a novel concept of the Fixed-Field-Alternating (FFA) small racetrack proton accelerator 10x6 size, with kinetic energy range between 30-250 MeV made of permanent magnets. The horizontal and vertical tunes are fixed within the energy range, as the magnets The combined function magnets have additional sextupole and octupole multipoles the chromatic corrections, providing very fast cycling with a frequency of 1.3 KHz. The injector is 30 MeV commercially available cyclotron with RF frequency of 65 MHz. The permanent magnet synchrotron RF frequency is 390 MHz and acceleration uses the phase jump scheme., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Conventional slow extraction driven by a tune sweep perturbs the optics and changes the presentation of the beam separatrix to the extraction septum during the spill. The constant optics slow extraction (COSE) technique, recently developed and deployed operationally at the CERN Super Proton Synchrotron to reduce beam loss on the extraction septum, was implemented at MedAustron to facilitate extraction with a tune sweep of operational beam quality. COSE fixes the optics of the extracted beam by scaling all machine settings with the beam rigidity following the extracted beam’s momentum. In this contribution the implementation of the COSE extraction technique is described before it is compared to the conventional tune sweep and operational betatron core driven cases using both simulations and recent measurements., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

In 2021 the Extra Low ENergy Antiproton ring (ELENA) moved from commissioning into the physics production phase providing 100 keV antiprotons to the newly connected experiments paving the way to an improved trapping efficiency by one to two orders of magnitude compared to the AD era. After recalling the major work undertaken during the CERN Long Shutdown 2 (2019-2020) in the antiproton deceleration complex, details will be given on the ELENA ring and the new electrostatic transfer line beam commissioning using an ion source. Sub-sequentially, the progress from commissioning with ions to operation with antiprotons will be described with emphasis on the achieved beam performance. Finally, the impact on the performance of the main hardware systems will be reviewed., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Physics Beyond Colliders (PBC) study investigates means of exploiting the potential of the CERN accelerator complex to complement the laboratory’s scientific programme at the main Large Hadron Collider (LHC) experiments. The LHC fixed-target (FT) working group studies new experiments at beam energies up to 7 TeV. One of the proposed experiments is based on a bent crystal, part of the collimation hierarchy, to extract secondary halo particles and steer them onto a target. A second bent crystal immediately downstream of the target is used to study electric and magnetic dipole moments of short-lived baryons. The possibility to install a test stand in the LHC off-momentum collimation Insertion Region (IR3) to demonstrate the feasibility and performance of this challenging scheme is currently under investigation. The integration of a spectrometer magnet into the present layout is particularly critical. In this contribution, we study a possible test setup that could be used in LHC Run 3., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Interaction of low-energy antiprotons with nuclear targets provided fundamental knowledge about proton and neutron densities of many nuclei through the capture process, cascade on lower electron orbits, and annihilation with the nucleon. The expelled electrons produce X-rays and with the recoil particles after annihilation, thus, a sufficient amount of information can be obtained about this interaction. However, all previous experiments were done via formation of antiprotonic atoms in solid or gaseous targets. Therefore, annihilation occurs prior reaching the S or P orbital levels and precise measurements are missing. Recently, AEgIS collaboration proposed a conceptually new experimental scheme. The creation of cold antiprotonic atoms in a vacuum guarantees the absence of the Stark effect. And with the sub-ns timing and synchronization, the previous experimental obstacles would be resolved. This will allow studying atomic properties, evolution, and fragmentation process with improved precision and extended lifetimes. In this contribution, we present an overview of the experimental scheme as well as various aspects of negative ion injection beamline into the AEgIS experiment., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Located at CERN, ISOLDE is one of the world’s lead-ing research facilities in the field of nuclear science. Radioactive Ion Beams (RIBs) are produced when 1.4 GeV protons transferred from the Proton Synchrotron Booster (PSB) to the facility impinge on one of the two available targets. The RIB of interest is extracted, mass-separated and transported to one of the experimental stations, either directly, or after being accelerated in the REX/HIE-ISOLDE post-accelerator. In addition to a Penning trap (REXTRAP) to accumulate and transversely cool the beam and a charge breeder (REXEBIS) to boost the charge state of the ions, the post-accelerator includes a linac with both room temperature (REX linac) and superconducting (HIE-ISOLDE linac) sections followed by three HEBT lines to deliver the beam to the different experimental stations. The latest upgrades of the facility as well as a comprehensive list of the RIBs delivered to the users of the facility and the operational experience gained during the last physics campaigns will be presented in this contribution., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The disk-loaded structures (DLS) in the muon LINAC are under development for the J-PARC muon g-2/EDM experiment. Four DLSs with an accelerating gradient of 20 MV/m take charge of muon acceleration from 40 MeV to 212 MeV, which corresponds to 70% to 94% of the speed of light. The quasi-constant gradient type TM01-2pi/3 mode DLSs with gradually varying disk spacing was designed and confirmed that the cumulative phase slip due to the mismatch between muon and phase velocity can be suppressed to less than 2 degrees at the frequency of 2592 MHz. In addition, the optimum synchronous phase and the lattice were investigated to satisfy the requirements of the total emittance less than 1.5 pi mm mrad and the momentum spread less than 0.1% in RMS., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

A new experiment to measure electric dipole moments (EDMs) of elementary particles, based on the Frequency Domain method, has been proposed for implementation at the NICA facility (JINR, Russia). EDM experiments in general, being measurement-of-polarization experiments, require long spin-coherence times at around 1,000 seconds. The FD method involves a further complication (well paid off in orders of precision) of switching the polarity of the guiding field as part of its CW-CCW injection procedure. This latter procedure necessitates a calibration process, during which the beam polarization axis changes its orientation from the radial (used for the measurement) to the vertical (used for the calibration) direction. If this change occurs adiabatically, the beam particles’ spin-vectors follow the direction of the polarization axis, which undermines the calibration technique; however, concerns were raised as to whether violation of adiabaticity could damage spin-coherence., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Crab cavity is essential for retrieving the loss in luminosity due to the large crossing angle in the two colliding beam lines of the Electron Ion Collider (EIC). Due to the asymmetric design of the proton beam crab cavity, the fundamental mode consists of contributions from higher order multipoles. These multipole modes may change during fabrication and installation of the cavities, and therefore affect the local dynamic aperture. Thresholds for each order of the multipoles are applied to ensure dynamic aperture requirements at these crab cavities. In this paper, we analyzed the strength of the multipoles due to fabrication and installation accuracies, and set limitations to each procedure to maintain the dynamic aperture requirement., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

In the framework of the LHC Injectors Upgrade project, the Beam Gas Ionisation (BGI) profile monitors installed in the Proton Synchrotron (PS) were fitted with a gas injection system capable of boosting the signal rate high enough to capture single turn acquisitions immediately after injection. This contribution reports on the studies carried out during the beam commissioning of the BGI system in a turn-by-turn matching monitor mode for its eventual implementation in an optimisation framework to preserve emittance during transfer between the PS Booster and PS. The BGI commissioning included a benchmarking with data from a wire-grid secondary emission monitor inserted into the circulating beam., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The PS Booster (PSB) is the first synchrotron in the injection chain for protons. The beams produced for the LHC and various fixed target experiments cover a very large parameter space. Over the Long Shutdown 2 (LS2), the PSB was heavily upgraded as part of the LHC Injectors Upgrade (LIU) project. The low-level RF systems now drive the new Finemet-loaded cavities, control RF synchronisation for the new injection mechanism, and cope with the increased injection and extraction energies. The Finemet cavities provide exceptional flexibility, allowing an arbitrary distribution of voltage at different revolution frequency harmonics, but at the cost of significant broadband impedance. The new injection mechanism allows bunch-to-bucket multi-turn injection, which significantly reduces the amount of beam loss at the start of the cycle. The longitudinal beam production schema for each beam-type was developed based on simulations during LS2, and then adapted during the setting-up phase to suit the final operational configuration. This paper discusses the commissioning of the new LLRF, and the consequences of the LIU upgrades on the production of various beams., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

Fixed Field Alternating Gradient Accelerators have been proposed for a wide range of challenges, including rapid acceleration in a muon collider, and large energy acceptance beam transport for medical applications. A disadvantage of these proposals is the highly nonlinear field profile required to keep the tune energy-independent, known as the scaling condition. It has been shown computationally that approximately constant tunes can be achieved with the addition of nonlinear fields which do not follow this scaling law. However the impacts of these nonlinearities are not well understood. We present a new framework for adding nonlinearities to Fixed Field Accelerators, seeking a constant normalised focusing strength over the full energy range, and verify the results by simulation using Zgoubi. As a model use case, we investigate the degree of tune compensation that can be achieved in a Fixed Field Accelerator for ion cancer therapy., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand