Ultrafast electron diffraction (UED) is a growing accelerator application that enables the study of transient material processes at sub-picosecond timescales with nanometer spatial resolution. In this proceeding, we present simulations of the Cryogenic Brightness-Optimized Radiofrequency Gun (CYBORG) beamline using the General Particle Tracer (GPT) code that are optimized for the application of UED. We explore advantages of performing UED with a beamline equipped with a low intrinsic emittance photocathode, extraction fields approaching 200 MV/m, and a cathode temperature below 77 K. The electron beam bunch length and the 4D transverse emittance are critical metrics for achieving high spatial and temporal resolution in UED, and are minimized at the sample location in our optimization using a Non-Dominated Sorting Genetic Algorithm II (NSGA II).

Many mature methods to measure the betatron function of a lattice rely on beam position monitor (BPM) data and the model of the whole machine. In this study, specific sections of the Relativistic Heavy Ion Collider (RHIC) were analyzed, taking advantage of BPMs separated by drift spaces near interaction points (IPs) and B3/B4 magnet sections of RHIC. This (local) approach would provide a alternative measure of the linear optics at specific regions which can be compared to previous (global) methods. This process utilizes the phase transfer matrix built from existing BPM data from RHIC using Linear Regression (LR) techniques. Non-AC dipole BPM data as well as AC dipole data was used to measure the linear optics. It was found that the local method yields comparable beta beat to global methods; however, it differs significantly around IP6. This study demonstrates that using LR analysis has advantages and disadvantages, and that further studies are needed to improve the method.

Reduction of dynamic aperture encountered in 4th generation light sources presents a challenge for injection efficiency and commissioning. It’s possible that only after BBA and optics corrections are applied, will the dynamic aperture be sufficient for reasonable injection efficiency. Furthermore, it’s only after a circulating beam is established that BBA, BPM calibration, and other optics corrections can be applied. Limited dynamic aperture not only makes standard top-up operation more challenging; during commissioning this challenge is even greater. To address this problem, we have developed a lattice design that allows for both low emittance optics (for standard user beam operation) and what we have called “commissioning optics” which is a set of lattice parameters that allows for larger dynamic aperture and Touschek Lifetime at the (temporary) cost of larger horizontal emittance.

Due to the constrains imposed by the tight geometry of the ALBA storage ring, the initial 6BA lattice envisioned for the ALBA-II upgrade was reconsidered in favor of a more relaxed 5BA configuration. The first engineering studies of magnets and vacuum chambers made evident many short comings of the 6BA optics. The here proposed 5BA optics allows for an easier integration at cost of a small increase of the natural emittance. The employed linear and non-linear optics optimization process is here described along with the first studies about dynamic aperture and lifetime.

Even though the strengths are weaker, different from quadrupole offsets, sextupole offsets are causing more complicated disturbances on the storage ring optics. They are making orbit distortion and quadrupole kicks as well as couplings. The offsets in chromatic sextupoles can affect the correction of chromaticity too. The closed orbit corrections in modern storage rings are fast and reliable, but their main focus is correcting the orbit to the quadrupole centers and the orbit distortion from a sextupole offset can make orbit offsets at other sextupoles which can be iterated. In this paper, we study the impact of the sextupole offsets on the linear optics in NSLS-II storage ring.

In this paper, we present a concise measurement of the Second-Order Transit Time Factor(TTF) of the relativistic electron beams within the bunching cavity of the Coherent Electron Cooling (CeC) Pop Experiment. Our study outlines a specialized measurement methodology that tackles the unique challenges posed by the CeC accelerator environment. The results not only provide significant insights into controlling CeC beam dynamics but also critically validate the theoretical prediction of the Second-Order TTF for relativistic electron beams. This work advances our understanding of beam dynamics and enhances the efficiency and control of CeC-based systems.

This paper presents the results of the IMPACT-T simulation conducted for the latest iteration of the Coherent Electron Cooling (CeC) Pop Experiment at Brookhaven National Laboratory (BNL). The CeC experiment aims to demonstrate the principles of CeC, a rapid cooling technique designed for high-energy hadron beams. In addition to presenting simulation results for the current lattice parameters, this paper includes a discussion of previous benchmarking results obtained from IMPACT-T simulations and real CeC experiments. These comprehensive simulations not only facilitate the fine-tuning of CeC lattice parameters but also offer insights into the ongoing performance enhancements, all aimed at achieving exceptional beam quality.

In this paper the beam-based alignment for solenoid and quadrupole magnets in the AREAL linear accelerator is presented. The AREAL accelerator, at this stage, operates with one solenoid, one quadrupole, corrector, and dipole magnets. The adjustment of solenoid and quadrupole magnets is crucial for the stable operation of the accelerator and for forming the desired beam required for the AREAL upgrade program. This work also takes into account the influence of the RF field radial component on the off-axis beam parameters and trajectory due to laser spot misalignment on the cathode. The study involves theoretical, simulation, and experimental comparisons.

Beam motion during injections could be a serious problem to x-ray users and jeopardize their experiments. In the Cornell Electron Storage Ring (CESR) the particles are injected with pulsed elements such as pulsed bumpers and septum which could cause transient motion of the stored beam. By analyzing the turn-by-turn position data of the stored beam acquired during injection, we identify the source of beam motion in different time scales. A new corrector coil is then designed to compensate the beam motion with 0.15 msec duration at a 60 Hz repetition rate in the vertical plane. In addition to the new corrector we also use one of the existing magnet coils to correct 60 Hz kicks and DC offsets. Although, during the last summer down the 60 Hz source was identified and suppressed by an order of magnitude, this corrector is still in use to minimize the injection transient. The waveforms, used to drive the correctors, are extracted based on the beam turn-by-turn coordinates and orbit kick analyses using the 110 CESR Beam Position Monitors data. In this paper we discuss the requirements and parameters of the new corrector, as well as the correction technique, which is proven to be effective.

Ultrafast electron diffraction (UED) is a growing accelerator application that enables the study of transient material processes at sub-picosecond timescales with nanometer spatial resolution. In this proceeding, we present simulations of the Cryogenic Brightness-Optimized Radiofrequency Gun (CYBORG) beamline using the General Particle Tracer (GPT) code that are optimized for the application of UED. We explore advantages of performing UED with a beamline equipped with a low intrinsic emittance photocathode, extraction fields approaching 200 MV/m, and a cathode temperature below 77 K. The electron beam bunch length and the 4D transverse emittance are critical metrics for achieving high spatial and temporal resolution in UED, and are minimized at the sample location in our optimization using a Non-Dominated Sorting Genetic Algorithm II (NSGA II).

The AGS Booster synchrotron at Brookhaven National Laboratory delivers resonant slow extracted beams to a fixed target beamline called the NASA Space Radiation Laboratory (NSRL). Experimenters at the NSRL require uniformly distributed radiation fields over large area to simulate the cosmic ray space radiation environment. The facility generates the uniform distribution using a pair of octupole magnets in the transport line. The beamline is designed to produce a achromatic optics through the octupoles and to the target. However, the dispersion function depends on the trajectory of the beam as it is transported out of the booster and into the NSRL beamline. The dependence on this trajectory has not been previously studied. In this paper, we describe a new model we have developed to study this effect and show measurements to compare to our simulations.

The low emittance ( 4th generation) light source Elettra 2.0, that will replace Elettra the 3rd generation light source in Trieste Italy, will be commissioned in 2026. However the injector complex will be conserved but improvements will be done in order to be ready before of the storage ring commissioning. Optics modification, hardware upgrade and software development will be undertaken to improve the performance, stability and reliability of the Injector complex

The design of a helium synchrotron for cancer therapy is being studied and optimized in the context of the Next Ion Medical Machine Study (NIMMS) at CERN. In particular, the effects of combined-function magnets and their geometry on the optics functions and hence on the beam size are evaluated. Moreover, the introduction of defocusing quadrupoles in the lattice is investigated as a means of better controlling the optics in both planes, while sextupoles for chromaticity control and resonant extraction are introduced. The updated lattice design is simulated to identify potential limitations in terms of nonlinear dynamics due to the low periodicity of the lattice and propose a regime for operations from the transverse beam dynamics’ perspective.

In a circular collider, precise control of the linear optics in the vicinity of the interaction points plays a crucial role in ensuring optimal operational performance and satisfying the machine protection constraints. Superconducting magnets are affected by unavoidable field errors that impact machine performance, and mitigation strategies are usually put in place to improve the situation. Past studies performed on the LHC have shown the benefit of magnet sorting on both initial beta-beating, through compensation of magnetic field errors, and overall correction quality of the machine optics. This work aims at extending those studies in the context of the luminosity upgrade of the LHC by considering the possible impact on performance from various sorting strategies applied to the new triplet quadrupoles for the ATLAS and CMS high-luminosity insertions.

The European Synchrotron Radiation Facility (ESRF) presently operates with the Hybrid Multi-Bend Achromat (HMBA) lattice that features 𝛽-functions of 6.9 m and 2.7 m in the horizontal and vertical planes at the center of the straight sections. New optics were designed to increase the brilliance of beam lines with a single undulator placed at the center of the straight section. The reduction of the in-vacuum undulator gap and of the beta-functions both contribute to this increase. This paper reports on the optics beam commissioning results and experimental observation with the reduced in-vacuum undulator gap.

Many mature methods to measure the betatron function of a lattice rely on beam position monitor (BPM) data and the model of the whole machine. In this study, specific sections of the Relativistic Heavy Ion Collider (RHIC) were analyzed, taking advantage of BPMs separated by drift spaces near interaction points (IPs) and B3/B4 magnet sections of RHIC. This (local) approach would provide a alternative measure of the linear optics at specific regions which can be compared to previous (global) methods. This process utilizes the phase transfer matrix built from existing BPM data from RHIC using Linear Regression (LR) techniques. Non-AC dipole BPM data as well as AC dipole data was used to measure the linear optics. It was found that the local method yields comparable beta beat to global methods; however, it differs significantly around IP6. This study demonstrates that using LR analysis has advantages and disadvantages, and that further studies are needed to improve the method.

Nonlinear integrable optics are a promising alternative approach to lattice design. The integrable optics test accelerator (IOTA) at Fermilab has been constructed for dedicated studies of magnetostatic elliptical elements as described by Danilov and Nagaitsev. The most compelling verification of correct implementation of the NIO lattice is direct observation of the analytically expected invariants. This report outlines the experimental and analytical methods for extracting the nonlinear invariants of motion from data gathered in the last IOTA run.

One of the most promising advantages of nonlinear integrable optics is strong amplitude dependent tune shift without degrading the dynamic aperture. The integrable optics test accelerator (IOTA) at Fermilab is constructed around nonlinear lattice elements of the elliptical type as described by Danilov and Nagaitsev. Detuning and dynamic aperture scans in IOTA were performed using a fast dipole kicker and a low emittance electron beam. The evolution of the dynamic aperture and detuning for different configurations of the integrable optics lattice are presented.

The upcoming Proton Improvement Plan-II (PIP-II), designated for enhancements to the Fermilab accelerator complex, features a Beam Transfer Line (BTL) that channels the beam from the linac exit to the booster. In the absence of longitudinal focusing beyond the superconducting linac, the beam experiences an elevated momentum spread, primarily due to nonlinear space-charge forces, surpassing the allowable limit of 2.1e-4. This study presents a detailed examination of the space-charge-induced momentum spread and outlines mitigative strategies. The investigation includes the fine-tuning of a de-buncher cavity, analyzed in terms of operating frequency, longitudinal location, and gap voltage, under both standard and perturbed beam conditions—specifically accounting for momentum jitter and energy variation. The impact of buncher cavity misalignments on the beam's longitudinal phase space is also assessed. The paper concludes by recommending an optimized cavity configuration to effectively mitigate the observed increase in momentum spread along the BTL.

Integrable systems possess a hidden symmetry associated with the existence of conserved quantities known as integrals of motion. These systems play an important role in understanding general dynamics in accelerators and have potential for future designs. This work will cover two automated methods for finding integrable symplectic maps of the plane. The first algorithm is based on the observation that the evolution of an integrable system in phase space is confined to a lower-dimensional submanifold of a specific type. The second algorithm relies on an analysis of dynamical variables. Both methods rediscover some of the famous McMillan-Suris integrable mappings and ultra-discrete Painlev\'e equations. Over 100 new integrable families are presented and analyzed, some of which are isolated in the space of parameters, while others are families with one parameter (or the ratio of parameters) being either continuous or discrete. In addition, the newly discovered maps are related to a general 2D symplectic map through the use of discrete perturbation theory. A method is proposed for constructing smooth near-integrable dynamical systems based on mappings with polygon invariants.

The BESSY II Booster has been reliably delivering beam to the storage ring for several decades. As part of an effort to better understand and control beam dynamics in the Booster, new instrumentation, including Libera Spark ERXR beam position processors, has recently been installed and commissioned. These instrumentation upgrades have enabled measurements and corrections of optics parameters throughout the acceleration ramp which were not previously possible, leading to understanding and mitigation of mechanisms for beam loss and instabilities. Here we describe the beam position measurement system, corrections to the tune and chromaticity, and the resulting improvements to the top-up operation of BESSY II.

The high gradient of the photocathode radio-frequency electron gun (RF gun) increases the potential for field emission from the metal surface. Consequently, emitted electrons escaping from the RF gun result in the generation of a dark current, thereby degrading the gun's performance. A thorough investigation into the dark current phenomenon within the accelerator structure plays a crucial role in assessing the performance of the RF cavity and cathode, ensuring the accelerator operates under normal conditions. This paper focuses on establishing a transport matrix for off-axis particles in the RF gun and solenoid. This matrix predicates that field-emitted electrons tend to deviate from the center of the cathode. The study delves into both transverse and longitudinal dynamics characteristics of particles. By numerically tracking the path of dark electrons, we achieved a notable alignment between theoretical prediction and simulation results.

The compact storage ring project for accelerator research and technology (cSTART) is realized at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). Flexible lattice of a ring benefits variety of operation modes. Different physical experiments are planned at cSTART. In particular, deep variation of momentum compaction factor with simultaneous control of high order terms of alpha would demonstrate the capture and storage of ultra-short bunches of electrons in a circular accelerator. Computer studies of linear and non-linear beam dynamics were performed with an objective to estimate arrangement and performance of dedicated three pole chicane magnets to provide quasi-isochronous conditions for electrons. Additional families of so called “longitudinal” sextupoles and octupoles were added in a ring model to control slope and curvature of momentum compaction factor as function of energy offset of particles in a bunch.

The Los Alamos Neutron Science Center (LANSCE) accelerator produces high intensity H+ and H- beams for multiple experiments in fundamental and national security science. The proposed LANSCE Modernization Project (LAMP) is evaluating necessary upgrades to enable continuous LANSCE operations in years to come. LAMP seeks to upgrade the H+ and H- 750 kV Cockcroft-Walton (CW) generators with a dual-beam, 3-MeV Radiofrequency Quadrupole (RFQ). For technology maturation and know-how associated with this concept, an RFQ test stand with LAMP-like layout is being set-up to demonstrate dual-beam operation in an RFQ with all beam patterns required by experiments. The RFQ test stand will have 35-keV H+ and H- beamlines that simultaneously inject into a 750 keV RFQ. Assembly and initial characterization of the H+ beam is under way. The H- beamline has stringent requirements and will also demonstrate systems like a beam chopper and a low frequency buncher to produce required beam patterns. We describe the design of the H- beamline based on accelerator codes Warp and Impact.

The Los Alamos Neutron Science Center (LANSCE) accelerator delivers high intensity proton beams for fundamental science and national security experiments since 1972. The Proton Storage Ring (PSR) accumulates a full 625-us macro-pulse of proton beam and compresses it into a 290-ns long pulse, delivering an intense beam pulse to the Lujan Neutron Science target. The proposed LANSCE Modernization Project (LAMP) is evaluating necessary upgrades to the accelerator that will guarantee continuous beam operations in the next decades. Upgrades to the PSR and its high-energy injection and extraction beamlines are being considered to handle the higher beam intensity enabled by the LAMP upgrades in the front-end. For the PSR upgrades studies, we are building models of the PSR injection and extraction lines in codes which include space charge calculations like Elegant and Impact. These better illustrate the beam dispersion and the beam halo in the high-energy transport. This work describes the LANSCE PSR injection and extraction lines and the corresponding simulation models. The models are compared to available beam diagnostics data where available.

The Los Alamos Neutron Science Center (LANSCE) accelerator delivers high intensity proton beams for fundamental science and national security applications since 1972. LANSCE is capable of simultaneous H+ and H- beam operations to multiple experiments requiring different time structures. This is achieved upstream in the facility with a combination of two 750 kV Cockcroft-Walton (CW) generators, a chopper and radiofrequency cavities, before going into the 800-MeV linac. The proposed LANSCE Modernization Project (LAMP) is evaluating critical machine upgrades necessary to continuous beam operations in decades to come. A significant component of LAMP is replacing the two CW with a dual-species 3-MeV Radiofrequency Quadrupole (RFQ). This change requires a full re-design of the LAMP front-end accelerator to deliver the existing and expanded capabilities of the facility. This contribution will discuss the LAMP front-end accelerator layout based on the general beam requirements and on standard accelerator codes, showcasing the start-to-end propagation of H+ and H- beams from the source to the linac entrance.

A Laser Assisted Charge Exchange (LACE) injection in the Spallation Neutron Source (SNS) is under development. By utilizing powerful lasers and magnetic fields, electrons are stripped out of the H- beam without foils. Such a process avoids any foil-based charge exchange injection problems, such as foil degradation and beam loss, especially for future multi-megawatt power beams. Proof-of-principle of LACE has been experimentally demonstrated in the SNS in a transport line. Integration of the LACE injection into the SNS accumulator ring is in progress. In this paper, we present preliminary results of optics design and beam dynamics study.

We propose to correct nonlinear lattice optics with the closed-orbit modulation technique. Closed orbit modulation with large amplitude samples the nonlinear optics. Fitting such data measured on the machine to the lattice model with appropriate lattice parameters would reveal the nonlinear errors and provide a means for correction. The method is tested in simulation and is shown to work in principle. Experimental data were also taken. However, more work is needed to understand the other effects on the mode amplitude dependence on modulation amplitude on a real machine.

The RUEDI (Relativistic Ultrafast Electron Diffraction & Imaging) ultrafast electron diffraction (UED) beamline aims to provide electron bunches to diffraction samples with an at-sample temporal resolution of sub-10 fs. Electron bunches of such short duration prove non-trivial to measure at electron beam kinetic energies of 4 MeV. A diagnostic beamline design is presented to enable simultaneous longitudinal phase space measurements (bunch duration, momentum and momentum spread) with a streaker and spectrometer. Several methods of measuring sub-10 fs bunch durations using both RF transverse deflecting cavities and THz streakers are outlined here with their limitations. Measurements are replicated in simulation to demonstrate the diagnostic beamline is capable of the high-resolution required for the longitudinal phase space measurements within the RUEDI UED beamline.

The SSRF storage ring has been upgraded to an asymmetric lattice containing two super-bend cells, two double-mini-βy optics (DMB) cells and a superconducting wiggler (SCW) in 2019. Due to the destruction in structural symmetry, the restoration of linear optics becomes an essential issue in commissioning and routine beam dynamics maintenance. During the initial commissioning, the linear optics were well corrected with the LOCO method even though the SCW had not yet been installed. Recently, it has been found that the setups of some quadrupole power supplies tend to exceed the limits and deviate significantly from the intrinsic theoretical values, and the beta-functions and the tunes cannot be commendably recovered, leading to degradation of the storage ring performance. In this paper, the linear optics correction of the SSRF storage ring is introduced, the difficulties of the linear optics correction in asymmetric lattice are investigated, and the improved correction method and related application results are introduced.

The Shanghai Synchrotron Radiation Facility upgrade (SSRF-U) lattice is a 4th generation, 3 GeV, upgrade plan for SSRF. It aims to reach the diffraction limit while keeping the existing beam lines and spaces. The majority of insertion devices (IDs) in operation of current SSRF will be considered as the ID scheme in SSRF-U. The kick-map method has been used to build ID models, including the EPUs and SCW. Optical distortion caused by IDs was compensated using both local and global corrections. Then, frequency map analysis (FMA) method was used to identify potentially dangerous resonance lines. After considering high-order magnetic field errors, the dynamic aperture, energy acceptance, and Touschek lifetime were examined.

For the injection into the SOLEIL II storage ring a beam with small transverse and longitudinal sizes is necessary, which requires the booster synchrotron to be upgraded. The new booster is designed as a multi-bend 16BA Higher-Order Achromat lattice with a small emittance of 5 nm∙rad at 2.75 GeV. Robustness of the lattice has been studied with realistic errors in magnet alignment and calibration, but also taking into account specific errors as mismatch in the RF frequency and circumference error, as RF frequency is driven by the main storage ring. Also, power supply tracking errors have been considered and their reduction will be discussed. On top of these error studies an emittance exchange is performed to allow more flexibility in the injection parameters into the storage ring. Different methods are compared within the framework of a very realistic machine.

Thomas Jefferson National Accelerator Facility (Jefferson Lab) currently studies the feasibility of upgrading its energy to 22GeV. It considers addition of six more linac passes. The highest energy passes will share two new arcs designed using the Fixed-Field Alternating Gradient (FFA) technology. The FFA arcs are built using permanent combined-function magnets. They will be connected to the linacs through transition sections that will match the optics of all six passes to the linacs. With the high number of constraints and the limited space available, we are investigating a parametric resonance technique to match the optics quasi-independently at each energy. A resonance is excited at each individual energy to selectively control its optics. The resonant dipole and quadrupole kick harmonics are imposed for all energies simultaneously using Panofsky corrector magnets placed throughout the FFA arcs. This paper presents the current progress on that transition section design.

An upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (JLAB) is anticipated to provide an electron beam of over 20 GeV using the existing superconducting-RF linear accelerator and new fixed-field alternating (FFA) gradient recirculation arcs made up of Halbach-style permanent magnets. In the current design, the FFA arcs will carry six beams with energies of approximately 11, 13, 16, 18, 20, and 22 GeV which will require horizontal splitter lines to match the beam from the preceding linac. In this paper, we describe two alternative splitter beamline designs that are tuned to match the beam's Twiss parameters, R56, time-of-flight, bend-plane offset, and dispersion into the FFA cells.

Thomas Jefferson National Accelerator Facility (Jefferson Lab) is currently studying the feasibility of an energy upgrade based upon Fixed-Field Alternating Gradient (FFA) permanent magnet technology. The current plan is to replace the highest-energy recirculation arcs with FFA arcs, increasing the total number of beam recirculations, thus the energy. In order to accommodate multiple passes in the FFA arcs, horizontal splitters are being designed to control the beam parameters entering the FFA arcs, as well as time-of-flight and R56. In the current design, six passes will recirculate through the FFA arcs, necessitating the design of six independent beamlines to control the optics and beam dynamics matching into the arcs. These beamlines must fit into the current CEBAF tunnel while allowing for personnel and equipment access. They must also be flexible enough to accommodate the beam under realistic operational conditions and fluctuations. The constraints on the system are highly restrictive, complicating the design. This document will describe the current state of the design and indicate the work remaining for a complete conceptual design.

The Electron-Ion Collider (EIC) is currently under development to be built at Brookhaven National Lab and requires cooling during collisions in order to preserve the quality of the hadron beam despite degradation due to intra-beam scattering and beam-beam effect. An Energy Recovery Linac (ERL) is being designed to deliver the necessary electron beam for Coherent electron Cooling (CeC) of the hadron beam, with an electron bunch charge of 1 nC and an average current of 100 mA; two modes of operation are being developed for 150 and 55 MeV electrons, corresponding to 275 and 100 GeV protons. The injector of this Strong Hadron Cooler ERL (SHC-ERL) is shared with the Precooler ERL, which cools lower energy proton beams via bunched beam cooling, as used in the Low Energy RHIC electron Cooling (LEReC). This paper reviews the current state of the design.

We describe experimental, theoretical, and simulation activities testing Derbenev’s 1998 proposal for using flat-to-round-to-flat (FTRTF) transformations to enable electron synchrotrons for ion beam cooling. FTRTF systems have also been proposed for storage-ring and single-pass light sources (FELs), beam sources, and microwave tubes. The experiment—based on a low-energy (5–10 keV) linear electron transport system—includes an electron source, beam-shaping aperture plate, quadrupole matching section, Derbenev skew-quadrupole vortex sections, and a long solenoid. Our theoretical efforts explore the optical conditions required to optimize the canceling of angular momenta at the core of the Derbenev system. The complexity of the beam dynamics requires the use of simulation codes—here WARP and OPAL—to model the system for comparison with experiment. To reduce the computational effort required for optimization, we introduce the use of the adjoint technique, well-known in plasma physics but not beam physics. Using 5–10 keV beams allows us to study beam dynamics over a broad range of space charge in an environment readily accessible to students.

The design of accelerator lattices involves evaluating and optimizing Figures of Merit (FoMs) that characterize a beam's properties. These properties (hence the FoMs) depend on the many parameters that describe a lattice, including the strengths, locations, and possible misalignments of focusing elements. We have developed efficient algorithms to determine the multi-parameter dependence of an FoM, taking advantage of recent developments in adjoint techniques that facilitate the efficient computation of FoM derivatives with respect to the many parameters that describe a lattice. One algorithm applies to lattices and beams for which the paraxial approximation holds and particle motion is described as 4D in transverse phase space with distance along the beam path as the independent variable. Another algorithm—appropriate for implementation in a code such as OPAL—applies to beams in which particle trajectories are calculated in 6D phase space with time as the independent variable. We describe both the underlying adjoint theory and the numerical implementation of these algorithms.

We present simulations compared to an experiment based on Derbenev’s flat-to-round (FTR) transformation designed to match an electron beam from a high energy storage ring into a solenoidal cooling channel. Our experiment transports a large-aspect-ratio electron beam through a skew quadrupole system and a long solenoid. We focus on examining the complex dynamics of FTR systems in low-energy electron beams where space charge is a major factor. We explore the interplay of angular momentum imparted by the skew quadruples with emittance and space charge in the transport system. We have found that while the envelope equations accurately predict averaged beam parameters, beam evolution details depend on the initial beam distribution. We present simulation results that illuminate the complex interplay of emittance, space charge, and angular momentum in non-ideal beam distributions, and we test our understanding against experimental results described elsewhere in these proceedings.

The demands of a higher brightness photon beam push the electron beam emittance of storage rings towards a diffraction-limited level. The concept of multi-bend achromat (MBA) structure and its variations, containing multiple dipoles in a cell, has been widely employed in the fourth-generation storage ring light sources. Recently, a novel concept of lattice structure, called complex bend lattice, extends the option for low emittance ring lattice design. This paper presents the developed low-emittance complex bend lattices. The benefits of using complex bends include low natural emittance, long straights for IDs, more free space for accelerator equipment, and reduced power consumption for magnets.

Synchrotron light source storage rings aim to maintain a continuous beam current without observable beam motion during injection. One element that paves the way to this target is the non-linear kicker (NLK). The field distribution it generates poses challenges for optimizing the topping-up operation. Within this study, a reinforcement learning agent was developed and trained to optimize the NLK operation parameters. We present the models employed, the optimization process, and the achieved results.