Leveraging raytracing softwares in diffraction-limited beamline design and simulation (Conference Presentation)

The design of beamlines for diffraction-limited storage rings light source (DLSR) requires the ability to simulate and optimize the performances of the photon transport schemes, as the brightness and coherence of the beam can rapidly be altered by optical, mechanical and thermal effects. Open source tools based on raytracing such as ShadowOUI/OASYS [1] have gained popularity in the community because of their time-tested reliability, their user-friendly interface and their flexibility, allowing to easily share designs and implement new capabilities (widgets) for analysis. While these tools offer fast and efficient computation for incoherent systems, only few extensions exist [2] to account for the coherent nature of the light produced by fourth generation light sources, or to quickly iterate the designs using other simulation frameworks [3] and discuss the performance trade-offs with the beamline scientists [4]. We have developed new tools to analyze wavefront based on optical path length, simulate the effect of misalignments [5] and thermal deformations, optimize adaptive optics shapes [6,7] to compensate them and devise optimal mirror profiles [8]. We have integrated these extensions as widgets for OASYS [9] and validated simulations results using experimental data based on wavefront sensor measurements, allowing us to refined tolerance specifications on mirror specifications, alignment and mechanical stability. These tools are now available to the x-ray community at large. References: [1] L. Rebuffi, M. Sanchez del Rio, "OASYS (OrAnge SYnchrotron Suite): an open-source graphical environment for x-ray virtual xperiments”, Proc. SPIE 10388, 103880S (2017) [2] X. Shi, R. Reininger, M. Sanchez del Rio, L. Assoufid, “A hybrid method for X-ray optics simulation: combining geometric ray-tracing and wavefront propagation”, J. Synchrotron Rad. 21, 669 (2014). DOI:10.1107/S160057751400650X [3] Wiegart, L., Rakitin, M., Zhang, Y., & Fluerasu, A. (2019). Towards the Simulation of Partially Coherent X-ray Scattering Experiments. In AIP Conference Proceedings (Vol. 2054, p. 060079). http://doi.org/10.1063/1.5084710 [4] Shi, X., Reininger, R., Harder, R., & Haeffner, D. (2017). X-ray optics simulation and beamline design for the APS upgrade. Advances in Computational Methods for X-Ray Optics IV, 10388, 12. http://doi.org/10.1117/12.2274571 [5] Wojdyla A., Bryant D., Cocco D., Dovillaire G., Warwick T., Rebuffi L., Idir M., Assoufid L., Goldberg K. A. (2018). Fine alignment of x-ray optics using wavefront sensor measurements. International Workshop on X-Ray Metrology. http://antoine.wojdyla.fr/assets/posters/iwxm2018.pdf [6] Alcock, S. G., Nistea, I.-T., Signorato, R., & Sawhney, K. (2019). Dynamic adaptive X-ray optics. Part I. Time-resolved optical metrology investigation of the bending behaviour of piezoelectric bimorph deformable X-ray mirrors. Journal of Synchrotron Radiation, 26(1), 36–44. http://doi.org/10.1107/S1600577518015953 [7] Ichii, Y., Okada, H., Nakamori, H., Ueda, A., Yamaguchi, H., Matsuyama, S., & Yamauchi, K. (2019). Development of a glue-free bimorph mirror for use in vacuum chambers. Review of Scientific Instruments, 90, 021702. http://doi.org/10.1063/1.5066105 [8] McKinney, W. R., Glossinger, J. M., Padmore, H. a., & Howells, M. R. (2009). Optical path function calculation for an incoming cylindrical wave. In Proc. of SPIE (Vol. 7448, pp. 744809-744809–8). http://doi.org/10.1117/12.828490 [9] https://github.com/oasys-als-kit/OASYS1-ALS-ShadowOui