Study On X-ray Differential Interference Imaging And Phase Shift Retrieval By Using A Zone Plate Pair

In the inertial confinement fusion (ICF) experiment, the rising of hydrodynamics instabilities can prevent the formation of central hot spot and destruct the shell of the target. The high resolution diagnostic methods are helpful for both monitoring the process of the hydrodynamics instability and reducing the defects of the target which are the seeds of the instabilities, which make it is important for studying the ICF.The X-ray, own to its short wavelength and high penetrability, can detect the internal structures and is generally used for the diagnosis in ICF. The contrast of traditional X-ray imaging method is formed through light be absorbed by object However, the ICF target, which is mainly consisted of Deuterium (D) and Tritium(T), has much lower absorption than refraction for X-ray. Thus, for imaging the ICF target, the technique utilizes the variations of phase shift to enhance the contrast is more favored than absorption-based method.In this paper, we combined phase contrast technique with the zone plate imaging and present a method for nanometer-resolution X-ray imaging as well as phase retrieval by one zone plate pair (ZPP). According to the theoretical analysis,the spatial resolution by this method would be pushed into the limiting resolution of zone plate. The following numerical simulations also support our theoretical analysis,in which we use a ZPP with the 80 nm outmost half-wave zone width and the spatial resolution in the retrieved phase shift and the transmittance are found to be 97.7 nm and 78.1 nm.In the last part of this paper, we give the preliminary study of three-dimensional phase-shift reconstruction which is on the basis of our method and uses the different angle of projection of the object to realize the reconstruction. The numerical simulations are carried out and use filtered backprojection algorithm. The results indicate our method can well reconstruct the refractive index.