Differential x-ray phase contrast imaging using a shearing interferometer

Abstract

An x-ray interferometer has been developed that uses two transmission phase gratings to analyze wave front distortions in the hard x-ray range. The interferometer is insensitive to mechanical drift and vibrations, and it is tunable over a wide range of photon energies. This setup was used for differential phase contrast imaging of low-absorbing test objects. We obtained micrographs with moiré fringes of good visibility, which revealed the local phase shift gradient caused by the objects. A comparison with numerically simulated images indicates that quantitative analysis of unknown phase objects is possible.

Performance and optimization of X-ray grating interferometry

“…Figure 1 shows a schematic of a typical grating interferometer and its geometric parameters. It can be distinguished between two types of interferometers, the Talbot-type interferometer [1,2], which uses two gratings (G1 and G2), and the Talbot-Lau-type interferometer [4], which uses an additional grating (G0). The beam splitter grating, or G1, is a phase grating which generates a periodic interference pattern of period p 2 with maximum intensity oscillations at the distances d = d m , which are given by [16] Figure 1.…”

EVITA Project: Comparison Between Traditional Non-Destructive Techniques and Phase Contrast X-Ray Imaging Applied to Aerospace Carbon Fibre Reinforced Polymer

“…It consists of a standard high power X-ray source (Varian HPW-160-11) and pixelated detector array (Dexela DEX2315) coupled to three gratings forming an X-ray interferometer. The principle of the X-ray grating interferometer is explained in details in the literature [1][2][3]13]. A collimator made out of lead is used to control the illuminated area while a shutter allows to block the X-ray beam during the idle time of the detector.…”

“…Grating-based Phase Contrast X-Ray Imaging is based on the so-called Talbot-Lau interferometer, which is made of the combination of a standard X-ray apparatus with three transmission gratings as documented in the literature [1][2][3][4]. The method derives its potential from the fact that three different contrast mechanisms are combined in a single measurement.…”

Surfing the spectrum – what is on the horizon?

“…73 Sophisticated equipment is required to produce the phase contrast of the waves, e.g., a synchrotron, which was unacceptable clinically due to size and cost, and historically crystals split the beams to enable phase differences, but these were unstable and gave a small field of view. Micro-focus X-ray tubes are being successfully operated to generate the beam but also have limited field of view 74 . X-ray…”