X-ray wavefront sensing and optics metrology using a microfocus x-ray grating interferometer with electromagnetic phase stepping

Abstract

A metrology method of x-ray optical elements based on an electromagnetic phase stepping x-ray grating interferometer with high slope accuracy is presented in this study. The device consists of an x-ray tube, a phase grating [Formula: see text] for modulating the incoming wavefront, and an absorption grating [Formula: see text] as a transmission mask to produce a broader moiré pattern for the x-ray camera. The focal spot of the microfocus x-ray source is shifted by a magnetic field from a solenoid coil. Electromagnetic phase stepping analysis is used to obtain a pixel-wise map of the wavefront phase distortion to replace the traditional precision mechanical scanning system, improving stability, speed, accuracy, and flexibility. The x-ray grating interferometer can be used as a feedback tool for evaluating the quality of optical elements and detecting defects caused by the x-ray beam or the x-ray optical elements in ordinary laboratories and mirror-processing centers without the need of scheduling synchrotron beam time.

Printed Silk Microelectrode Arrays for Electrophysiological Recording and Controlled Drug Delivery

“…Instabilities in soft polymeric films due to high electric field strength have been described before. [ 45,46 ] Here, the conductive carbon filler material could effectively reduce the length of dielectric bridges leading to an effective increase of local electric field strength and local breakdown.…”