A Super-high Angular Resolution Principle for Coded-mask X-ray Imaging Beyond the Diffraction Limit of Single Pinhole

TL;DR

This paper introduces a novel super-high angular resolution principle for coded-mask X-ray imaging that surpasses the diffraction limit using the DICC method, enabling precise astrophysical and solar observations.

Contribution

The paper develops the DICC reconstruction method and proposes the SHARP principle, demonstrating super-high resolution imaging beyond the diffraction limit with simulations.

Findings

Achieved angular resolution of 0.32 arcsec at 10 keV

Source location accuracy better than 0.02 arcsec

Demonstrated feasibility beyond the diffraction limit

Abstract

High angular resolution X-ray imaging is always demanded by astrophysics and solar physics, which can be realized by coded-mask imaging with very long mask-detector distance in principle. Previously the diffraction-interference effect has been thought to degrade coded-mask imaging performance dramatically at low energy end with very long mask-detector distance. In this work the diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method (DICC) is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle (SHARP) for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of single pinhole is demonstrated with simulations. With the specification that the mask element size of 50* 50 square micrometers and the mask-detector distance of 50 m, the achieved angular resolution is 0.32 arcsec above about 10 keV, and 0.36 arcsec at 1.24 keV where diffraction can not be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also shortly discussed.