Advanced high resolution x-ray diagnostic for HEDP experiments

A Ya Faenov ,R Kodama,A Casner,B Albertazzi,K A Tanaka,Th Michel,Makina Yabashi ,Kohei Miyanishi ,Norimasa Ozaki ,T Yabuuchi,Takeshi Matsuoka ,P Mabey,Tadashi Togashi ,Sergey Makarov ,Yuichi Inubushi ,Koji Takahashi ,G Rigon,Kento Katagiri ,A V Buzmakov ,S A Pikuz,T A Pikuz,M Kœnig

doi:10.1038/s41598-018-34717-9

Abstract

High resolution X-ray imaging is crucial for many high energy density physics (HEDP) experiments. Recently developed techniques to improve resolution have, however, come at the cost of a decreased field of view. In this paper, an innovative experimental detector for X-ray imaging in the context of HEDP experiments with high spatial resolution, as well as a large field of view, is presented. The platform is based on coupling an X-ray backligther source with a Lithium Fluoride detector, characterized by its large dynamic range. A spatial resolution of 2 µm over a field of view greater than 2 mm2 is reported. The platform was benchmarked with both an X-ray free electron laser (XFEL) and an X-ray source produced by a short pulse laser. First, using a non-coherent short pulse laser-produced backlighter, reduced penumbra blurring, as a result of the large size of the X-ray source, is shown. Secondly, we demonstrate phase contrast imaging with a fully coherent monochromatic XFEL beam. Modeling of the absorption and phase contrast transmission of X-ray radiation passing through various targets is presented.

Highlights

X-ray imaging is a fundamental diagnostic in the high energy density physics (HEDP) community, finding use in a wide range of fields including laboratory astrophysics[1,2] and inertial confinement fusion research[3,4]
The results demonstrate that the Lithium Fluoride (LiF) detector, coupled with an X-ray backlighter source, represents an improvement on the experimental X-ray radiography platform, boasting a sufficiently large field of view to image an entire HEDP experiment, with a high spatial resolution
A second experiment employing phase contrast imaging with a coherent monochromatic X-ray free electron laser (XFEL) beam significantly increases the visibility of inhomogeneities in low absorption objects

Summary

Introduction

X-ray imaging is a fundamental diagnostic in the high energy density physics (HEDP) community, finding use in a wide range of fields including laboratory astrophysics[1,2] and inertial confinement fusion research[3,4]. Fresnel zone plates have been used to measure the spots of XFELs to a precision of 10 s of nm[23], as well as the X-rays produced in laser target interactions[24], yet their field of view is only several μm and are not compatible with HEDP experiments Other methods, such as, Kirkpatrick-Baez systems are employed at XFELs25 or in ICF experiments[26] to achieve a resolution of up to 8 μm, and a field of view on the order of tens of μm, yet for the latter case, this is still not sufficient to provide quality imaging for the capsule implosion. A model of the transmission function of the monochromatic XFEL beam passing through modulated targets used for RTI experiments and subsequently incident on the LiF detector is presented

Methods

Results

Conclusion