The HYBRID code is an efficient tool for beamline simulation.  It combines the geometric ray tracing and wavefront propagation. The code computes diffraction effects when the beam is clipped by an aperture or optics size and can simulate the effects of figure errors. It has been implemented into the ShadowVUI package in XOP and the OASYS-ShadowOUI. Aversion in Igor is also available upon request (contact Xianbo Shi)

The code is under development in collaboration with the Shanghai Synchrotron Radiation Facility.  It simulates the propagation of the Mutual Optical Intensity (MOI) function through non-ideal optics. The MOI code can provide the intensity profile, the wavefront and the local coherence function at any location along the beamline.

The optics group maintains the wavefront propagation codes based on the direct Fresnel-Kirshhoff integration and the stationary phase approximation for simulating figure error effects on grazing reflection mirrors.

Advanced techniques on wavefront and coherence measurements

The optics group is exploring various coherence characterization and wavefront sensing techniques based on the grating interferometry and speckle tracking. We focus on using the grating Talbot interferometry a the at-wavelength metrology and the wavefront sensing tools. We developed coherence measurement techniques using 2-D (checkerboard or circular) gratings.

Coherence measurements of an undulator beamline using checkerboard grating and circular grating.

The optics group staff provides support to APS and the APS upgrade project beamline optimization, optics simulation and beamline characterization (flux, beam size, beam vibration, wavefront and coherence).