The ALS-U project to upgrade the Advanced Light Source to a multi bend achromat lattice received CD-3 approval in 2022 marking the start of the construction phase for the Storage Ring. Construction of the accumulator under a prior CD-3A authorization is already well advanced. ALS-U promises to deliver diffraction limited performance in the soft x-ray range by lowering the horizontal emittance to about 70 pm rad resulting in two orders of magnitude brightness increase for soft x-rays compared to the current ALS. The design utilizes a nine bend achromat lattice, with reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. It is optimized to produce intense beams of soft x-rays, which offer spectroscopic contrast, nanometer-scale resolution, and broad temporal sensitivity. This paper presents the final design, prototype results as well as construction progress.

The ALS-U project to upgrade the Advanced Light Source to a multi bend achromat lattice received CD-1 approval in 2018 marking the end of its conceptual design phase. The ALS-U design promises to deliver diffraction limited performance in the soft x-ray range by lowering the horizontal emittance to about 70 pm rad resulting in two orders of magnitude brightness increase for soft x-rays compared to the current ALS. The design utilizes a nine bend achromat lattice, with reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. This paper presents recent design progress of the accelerator, as well as new results of the R&D program.

The ALS upgrade into a diffraction-limited soft x-rays light source requires a small emittance, which is achieved by much stronger focusing than in the present ALS. Very strong focusing elements and a relatively small vacuum chamber make the required rapid commissioning a significant challenge. This paper will describe the progress towards a start-to-end simulation of the machine commissioning and present first simulation results.

The ALS-U upgrade promises to deliver diffraction limited performance throughout the soft x-ray range by lowering the horizontal emittance to about 50 pm resulting in 2-3 orders of brightness increase for soft x-rays compared to the current ALS. The design utilizes a multi bend achromat lattice with on-axis swap-out injection and an accumulator ring. One central design goal is to install and commission ALS-U within a short dark period. This paper summarizes the status of the conceptual design of the accelerator, as well as some results of the R&D program that has been ongoing for the last 3 years.

Recent studies have shown that strong, alternating focusing magnets can be used to greatly increase the momentum acceptance of hadron therapy gantries. With the high gradients achievable with superconducting magnets a level of momentum acceptance can be reached which may have significant implications to medical gantries and to the introduction of superconducting technology in this area. The design of such a superconducting magnet system for a proton therapy gantry will be presented. The Canted-Cosine-Theta concept is extended to a curved magnet system generating the desired bending and alternating focusing fields for the achromatic optics. Magnetic, structural, and thermal analysis of this design is presented along with preliminary efforts towards fabrication and assembly of the curved magnet.

The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is proposing the upgrade of its synchrotron light source to reach soft x-ray diffraction limits within the present ALS footprint. The storage ring lattice design and optimization of this light source is one of the challenging aspects for this proposed upgrade. The candidate upgrade lattice needs not only to fulfill the physics design requirements such as brightness, injection efficiency and beam lifetime, but also to meet engineering constraints such as space limitations, maximum magnet strength as well as beamline port locations. In this paper, we will present the approach that we applied to design and optimize a multi-bend achromat based storage ring lattice for the proposed ALS upgrade.

Author(s): Steier, C; Anders, A; Byrd, J; Chow, K; Duarte, R; Jung, J; Luo, T; Nishimura, H; Oliver, T; Osborn, J; Padmore, H; Pappas, C; Robin, D; Sannibale, F; De Santis, S; Schlueter, R; Sun, C; Swenson, C; Venturini, M; Waldron, W; Wallen, E; Wan, W; Yang, Y | Abstract: Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs [1]. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An RaD program was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings. It involves many areas, and focuses on the specific needs of soft x-ray facilities [2]: NEG coating of small chambers, swap-out injection, bunch lengthening, magnets/radiation production, x-ray optics, and beam physics design optimization. Hardware prototypes have been built and concepts and equipment was tested in beam tests on the existing ALS.

Copyright © 2016 CC-BY-3.0 and by the respective authors. Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs [1]. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An R & D program was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings. It involves many areas, and focuses on the specific needs of soft x-ray facilities [2]: NEG coating of small chambers, swap-out injection, bunch lengthening, magnets/radiation production, x-ray optics, and beam physics design optimization. Hardware prototypes have been built and concepts and equipment was tested in beam tests on the existing ALS.

The Advanced Light Source (ALS) at Berkeley Lab remains one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is underway, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade [1], which reduces the horizontal emittance from 6.3 to 2.0 nm (2.5 nm effective). Magnets for this upgrade were installed in late 2012 and early 2013 followed by user operation with the reduced emittance.

The Advanced Light Source (ALS) at Berkeley Lab has been updated many times and remains as one of the brightest sources for soft x-rays worldwide. However, recent developments in technology, accelerator physics and simulation techniques open the door to much larger future brightness improvements. Similar to proposals at several other 3rd generation sources, this could be achieved by reducing the horizontal emittance with a new ring based on a multi-bend achromat lattice, reusing the existing tunnel, as well as much of the infrastructure and beamlines. After studying candidate lattice designs, development efforts in the last year have concentrated on technology and physics challenges in four main areas: Injection, Vacuum Systems, Magnets and Insertion Devices, as well as main and harmonic RF systems.

The Advanced Light Source (ALS) at Berkeley Lab has seen many upgrades over the years, keeping it one of the brightest sources for soft x-rays worldwide. Recent developments in magnet technology and lattice design appear to open the door for very large further increases in brightness [1], particularly by reducing the horizontal emittance, even within the space constraints of the existing tunnel. Initial studies for possible lattices will be presented that could approach the soft x-ray diffraction limit around 2 keV in both planes within the ALS footprint.Emerging scientific applications and experimental methods that would greatly benefit from ring based sources having much higher brightness and transverse coherence than present or near future storage ring facilities include nanometer imaging applications, X-ray correlation spectroscopy, diffraction microscopy, holography, ptychography, and resonant inelastic soft X-ray scattering at high resolution.

The size and weight of ion-beam cancer therapy gantries are frequently determined by a large aperture, curved, ninety degree, dipole magnet. The higher fields achievable with superconducting technology promise to greatly reduce the size and weight of this magnet and therefore also the gantry as a whole. This paper reports advances in the design of winding mandrels for curved, canted cosine-theta (CCT) magnets in the context of a preliminary magnet design for a proton gantry. The winding mandrel is integral to the CCT design and significantly affects the construction cost, stress management, winding feasibility, eddy current power losses, and field quality of the magnet. A laminated mandrel design using a minimum symmetry in the winding path is introduced and its feasibility demonstrated by a rapid prototype model. Piecewise construction of the mandrel using this laminated approach allows for increased manufacturing techniques and material choices. Sectioning the mandrel also reduces eddy currents produced during field changes accommodating the scan of beam energies during treatment. This symmetry concept can also greatly reduce the computational resources needed for 3D finite element calculations. It is shown that the small region of symmetry forming the laminations combined with periodic boundary conditions can model the entire magnet geometry disregarding the ends.

The Advanced Light Source (ALS) at Berkeley Lab has seen many upgrades over the years, keeping it one of the brightest sources for soft x-rays worldwide. Recent developments in magnet and vacuum technology, as well as lattice design (multi bend achromat lattices) appear to open the door for very large further increases in brightness [1]. This could be achieved by reducing the horizontal emittance, with the new ring remaining within the space constraints of the existing tunnel. Initial studies yielded candidate lattices which approach the soft x-ray diffraction limit in both planes within the ALS footprint (diffraction limit around 2 keV, compare projected brightness in Fig. 1).

The Advanced Light Source (ALS) at Berkeley Lab while one of the earliest 3rd generation light sources remains one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is currently under way, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade, which will reduce the horizontal emittance from 6.3 to 2.2 nm (2.6 nm effective). This will result in a brightness increase by a factor of three for bendmagnet beamlines and at least a factor of two for insertion device beamlines. Magnets for this upgrade are currently in production and will be installed starting later this year.

A conceptual design of curved superconducting magnet for a carbon therapy gantry has been proposed. The design can reduce the gantry's size and weight and make it more comparable with gantries used for proton therapy. In this paper we report on a combined function, 5 T, superconducting dipole magnet with a 260 mm bore diameter that is curved 90 degrees at a radius of 1269 mm. The magnet superimposes two layers of oppositely wound and skewed solenoids like windings, energized in a way that nulls the solenoid field and doubles the dipole field component. Furthermore, the combined architecture of the windings can create a selection of field terms that are off the near-pure dipole field. Combined harmonics such as a quadrupole and sextupole are needed to adjust the beam trajectory. Ways to adjust the field and beam trajectory, magnet size and assembly, structure and pre-stress are considered.

The Advanced Light Source (ALS) is a third-generation light source in operation since 1993. This light source is providing state-of-the-art performance to more than 40 beamlines and their users, due to the upgrades that have been completed over the last few years. The storage ring upgrade project that is developed here will allow the ALS to provide the 40 beamline users with higher photon beam brightness (factor of 2 or 3) by having its storage ring lattice modified. Forty-eight harmonic sextupole magnets with integrated dipole correctors and skew quadrupole coils will be introduced, which will require a level of installation activity not seen at the ALS since its original construction in 1991. Introducing new combined-function magnets in an existing storage ring is a challenge due to the limited space available and a balance had to be found between magnet performance and spatial constraints. After an introduction reviewing the characteristics of the three design families of the 48 combined-function magnets, the magnet fabrication and installation are developed along with analyses based on the magnetic measurements and the ALS storage ring commissioning results.

An upgrade project is under way to further improve the brightness of the Advanced Light Source at Berkeley Lab by reducing its horizontal emittance from 6.3 to 2.2nm (effective emittance in the straights from 6.4 to 2.5nm). This will result in a brightness increase by a factor of three for bend magnet beamlines and at least a factor of two for insertion device beamlines and will keep the ALS competitive with newer sources. This paper presents an overview of the upgrade project with emphasis on the nonlinear beam dynamics simulations. It also discusses in a more general way the techniques used at LBNL for finding optimum lattices (e.g. the ones with maximum brightness) and optimizing the particle dynamics, thereby increasing beam lifetime and stability.

A new method is developed to optimize low-emittance and low-beta lattices for ALS ultimate upgrade. The study provides us a different perspective on the lattice design, and confirms results early found using both Global Scan of All Stable Settings (GLASS) and Genetic Algorithms (GA) techniques.