Refractive X-ray imaging with multiple pencil beams

When spatially coherent X-ray beams pass through a sample, edge-enhancement is observed in the transmission X-ray image because of the refraction effect. At Canadian Light Source (Saskatoon, Saskatchewan, Canada), Professor P. C. Johns (Carleton University) and his colleague have recently reported an interesting extension of this type of X-ray refractive imaging. They used multiple pencil beams (up to five) to create both transmission and refractive projection images, simultaneously, during the sample scan crossing the beams. The radial data were extracted from the overlapped image by a Maximum Likelihood-Expectation Maximization (MLEM) algorithm. For more information, see the papers, "Synchrotron-based coherent scatter x-ray projection imaging using an array of monoenergetic pencil beams", K. Landheer et al., Rev. Sci. Instrum., 83, 095114 (2012).