Design and simulation of a monolithic thick-wall polycapillary X-ray lens for multipoint X-ray microscopy

A monolithic thick-wall polycapillary X-ray lens (MTW-PXRL) was designed to eliminate image splitting in a multipoint X-ray microscope, a limitation of traditional thin-walled PXRLs. The MTW-PXRL, composed of 1951 thick-walled monocapillaries, simplifies the experimental setup by eliminating the need for masks and optical alignment. A ray-tracing simulation program was developed to evaluate the performance of the MTW-PXRL in a multipoint X-ray microscope. The results show that the MTW-PXRL can generate a sparse secondary X-ray source array without image splitting and signal loss, enabling acquisition of 3D sample information in a single exposure. The effects of various MTW-PXRL parameters on multipoint projections were systematically examined by the simulation program. The projection resolution is now determined by the output inner diameter of the monocapillary, rather than the X-ray source size. Thus, this approach allows the use of a high-power laboratory X-ray source with a large focal spot, facilitating the development of rapid 3D X-ray microscopy.