SRW CRL - radiasoft/sirepo GitHub Wiki
Compound Refractive Lens (CRL) - https://en.wikipedia.org/wiki/Compound_refractive_lens.
See Dynamical-access-of-crystal-data-and-optical-constants-from-external-servers for details about automatic accessing the optical constants from http://henke.lbl.gov/optical_constants/.
Here is a YouTube video that demos how SRW can automatically obtain material properties for a compound refractive lens (CRL) from the online database maintained by the Center for X-ray Optics at LBL. CRL material properties taken from LBL database