The upgrade of the Advanced Light Source at Lawrence Berkeley National Lab to a Diffraction-Limited Storage Ring (DLSR) will feature four new and upgraded beamlines, designed to take full advantage of the coherence and high brightness of the insertion device source operating mostly in the soft x-ray regime (100–2000 eV). The round and highly coherent beam drives specific design choices for the photon transport optics and monochromator, and technical challenges in terms of performances, optical tolerances and stability. We have used the simulation tools Shadow (for raytracing) or SRW (wavefront propagation), and their implementation in OASYS and Sirepo to refine tolerance specifications, using their scripting capabilities and new add-ons to perform a comprehensive beamline analysis and confirm that specifications matched our performance requirements, taking into account partial coherence and issues related to heatload.
We describe the implementation of realistic, adaptive wavefront correction in high-brightness beamline simulations to study the correction of thermal deformation. Several planned soft x-ray and tender x-ray insertion-device beamlines in the Advanced Light Source upgrade, where wavefront preservation is paramount, rely on a common design principle.After studying the performance of a 20-channel adaptive x-ray mirror prototype, at-wavelength and with visible-light, we implemented mirror shape-control algorithms in software that are designed to restore and optimize the focused beam intensity (i.e. Strehl ratio), considering the incident wavefront’s phase and amplitude. We implemented the modeling in OASYS which is an adaptable, customizable beamline modeling platform well suited to study this issue.
In this paper we provide an update on the development of a novel cantilevered-liquid-nitrogen-cooled-silicon mirror for a new insertion device beamline included in the Advanced Light Source Upgrade (ALS-U). The goals of this mirror development are to achieve diffraction limited performance, demonstrate reliability, minimize coolant flow induced vibration, and demonstrate carbon contamination prevention and cleaning techniques. In this paper we summarize the design requirements, the design of the mirror system, and prototype fabrication.