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Abstract: A superconducting, combined-function, 5T, , toroidal magnet with a large bore is described in this paper. This magnet is designed to be the last and most difficult part of a compact superconducting magnet-based carbon gantry optics for ion beam cancer therapy. The relatively small size of this toroidal magnet allows for a gantry the size of which is smaller or at least comparable to that of a proton gantry. The gantry design places the toroidal magnet between the scanning magnets and the patient, that is the scanning magnets are placed midway through the gantry. By optimizing the coil winding configuration of this magnet, near point-to-parallel optics is achieved between the scanning magnets and the patient; while at the same time there is only a small distortion of the beam-shape when scanning. We show that the origin of the beam-shape distortion is the strong sextupole components, whose effects are greatly pronounced when the beam is widely steered in the magnet. A method to correct such an undesirable effect is suggested and demonstrated by a numerical particle tracking through the calculated three-dimensional magnetic field. [Copyright &y& Elsevier]

A state of the art X-ray photoemission electron microscope (PEEM2) is operational at the Advanced Light Source at a resolution of typically 50 nm for a range of chemical and magnetic surface studies. A new microscope, PEEM3, is under development with an aim of achieving a resolution of 5 nm and more than an order of magnitude increase in transmission at the nominal resolution of PEEM2. The resolution and flux improvement is realized by providing geometric and chromatic aberration compensations in the system using an electron mirror and a beam separator magnet. The nearly aberration-free design of the beam separator is critical to the performance of third generation PEEMs. In this paper, we present the optics design model, optimal operation parameters, analyses of aberration impact, as well as the mechanical alignment tolerance for PEEM3 separator prototypes. In particular, we emphasize the importance of a new semi-analytical approach to design complex charged particle optics using the truncated power series algebra. Because of its ability to compute high-order aberrations, this approach allows systematic and comprehensive analyses of any charged particle optics systems with analytical electric and magnetic fields. [Copyright &y& Elsevier]

After generating the first femto-second X-ray pulses at the Advanced Light Source (ALS), it becomes critical to improve the flux of this femto-second source for user experiments. A narrow-gap in-vacuum undulator has been proposed to be installed in one of the ALS straight sections. To realize the optimal performance of this undulator, a straight section lattice with a mini vertical beta function has been designed. Separation of electrons has been achieved by generating a sizable vertical dispersion via a local dispersion bump and a closed orbit bump. Particle tracking study shows that the modified ALS lattice for the femto-second X-ray source has an adequate dynamic aperture. [Copyright &y& Elsevier]

Abstract: As the result of an extensive long-term planning process involving all its stakeholders—management, staff, and users—the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2–3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates. [Copyright &y& Elsevier]

A third generation aberration-corrected Photoemission Electron Microscope is being designed at the Advanced Light Source. An electron mirror is used for the correction of the lowest order spherical and chromatic aberrations. Two very different methods, one using finite-element method and ray-tracing technique and the other using charge ring method and differential algebra technique, have been employed to simulate the electrostatic field and the behavior of the electron beam. Good agreement has been obtained between the two methods and a tetrode mirror has been found to effectively correct the spherical and chromatic aberrations. Operating at 20 kV, the point resolution for 100% transmission reaches 50 nm with the mirror corrector, a significant reduction from that of 440 nm without correction. The highest resolution achieved is 4 nm at 2% transmission, as opposed to 20 nm at 1% transmission without correction. [Copyright &y& Elsevier]