Phase-sensitive X-ray imager

1. A method for producing a simulated reconstructed x-ray wavefront, comprising:

propagating a first x-ray wavefront along an optical path defined from an x-ray source through a wavefront sensor element to a detector, wherein said detector detects a reference wavefront;

inserting a sample into said optical path between said x-ray source and said wavefront sensor;

propagating a second x-ray wavefront along said optical path and to said detector, wherein said detector detects a signal wavefront;

calculating a phase gradient between said reference wavefront and said signal wavefront;

simulating the propagation of said signal wavefront back to a simulated screen located at the position of said sample to produce a propagated wavefront;

adjusting said propagated wavefront with a percentage of said phase gradient to produce an adjusted wavefront;

simulating the propagation of said adjusted wavefront to said detector to produce a simulated signal wavefront;

calculating a subsequent phase gradient between said signal wavefront and said simulated signal wavefront;

simulating the propagation of said simulated signal wavefront back to said simulated screen to produce a second propagated wavefront;

adjusting said second propagated wavefront with a percentage of said subsequent phase gradient to produce a second adjusted wavefront;

simulating the propagation of said second adjusted wavefront to said detector to produce a reconstructed x-ray wavefront; and

displaying said reconstructed x-ray wavefront.

2. The method of claim 1 , further comprising providing said first x-ray wavefront and said second x-ray wavefront from a source selected from the group consisting of a free-electron laser, an x-ray tube, a laser-produced source, an x-pinch source, a synchrotron and a micro-focus tube.

3. The method of claim 1 , wherein said second x-ray wavefront comprises an energy within a range from about 100 eV to about 60 KeV.

4. The method of claim 1 , wherein said first x-ray wavefront and said second x-ray wavefront comprise a cross-sectional area that propagates according to a characterization selected from the group consisting of collimated, diverging and converging.

5. The method of claim 1 , wherein said wavefront sensor element comprises a Hartmann plate.

6. The method of claim 1 , wherein said wavefront sensor comprises a zone plate array.

7. The method of claim 1 , wherein said wavefront sensor element comprises crossed phase gratings.

8. The method of claim 7 , wherein said crossed phase gratings comprises first portions having a first index of refraction at the wavelength of said first x-ray wavefront and said second x-ray wavefront and wherein said crossed phase gratings comprise second portions having a second index of refraction at the wavelength of said first x-ray wavefront and said second x-ray wavefront, wherein said first index and said second index are different.

9. The method of claim 1 , wherein said detector is selected from the group consisting of a CCD camera, a scintillator, at least one phosphor screen, at least one imaging plate, an x-ray film and amorphous selenium.

10. The method of claim 1 , wherein said first detector is located at a distance d from said wavefront sensor, wherein said distance is selected from the group consisting of (i) between 0 and d 2 /λ; (ii) between d 2 /λ and 2d 2 /λ, where λ is the wavelength of the x-rays of said x-ray wavefront and (iii) multiples of these distances.

11. The method of claim 1 , further comprising measuring the intensity of said signal wavefront.

12. The method of claim 1 , wherein said first x-ray wavefront and said second x-ray wavefront are propagated from a backlighter selected from the group consisting of a spatially coherent backlighter and a periodic backlighter.

13. The method of claim 1 , further comprising:

calculating 1 to n subsequent phase gradients between said signal wavefront and 1 to n reconstructed x-ray wavefronts, where n is the number of iterations;

simulating the propagation of said 1 to n reconstructed x-ray wavefronts back to said simulated screen to produce 1 to n propagated wavefronts;

adjusting said 1 to n propagated wavefronts with a percentage of said 1 to n subsequent phase gradients to produce a 1 to n adjusted wavefronts; and

simulating the propagation of said 1 to n adjusted wavefronts to said detector to produce a final reconstructed x-ray wavefront determined, to have a desired phase gradient value.

14. An apparatus for producing a simulated reconstructed x-ray wavefront, comprising:

an x-ray source or providing at least one of a first x-ray wavefront and a second x-ray wavefront;

wavefront sensor element;

a detector;

wherein said x-ray source, said wavefront sensor element and said detector are aligned on an optical path defined from said x-ray source through said wavefront sensor element to said detector; and

a computer system comprises a processor and display, wherein said processor comprises an algorithm for carrying out a series of steps comprising:

calculating a phase gradient between a reference wavefront and a signal wavefront;

simulating the propagation of said signal wavefront hack to a simulated screen located, at the position of said sample to produce a propagated wavefront;

adjusting said propagated wavefront with a percentage of said phase gradient to produce an adjusted wavefront;

simulating the propagation of said adjusted wavefront to said detector to produce a simulated signal wavefront;

calculating a subsequent phase gradient between said signal wavefront and said simulated signal wavefront;

simulating the propagation of said simulated signal wavefront back to said simulated screen to produce a second propagated wavefront;

adjusting said second propagated wavefront with a percentage of said subsequent phase gradient to produce a second adjusted wavefront; and

simulating the propagation of said second adjusted wavefront to said detector to produce a reconstructed x-ray wavefront.

15. The apparatus of claim 14 , wherein said source is selected from the group consisting of a free-electron laser, an x-ray tube, a laser-produced source, an x-pinch source, a synchrotron and a micro-focus tube.

16. The apparatus of claim 14 , wherein said source is capable of producing an x-ray wavefront having an energy within a range from about 100 eV to about 60 KeV.

17. The apparatus of claim 14 , wherein said source is capable of producing an x-ray wavefront having a cross-sectional area selected from the group consisting of collimated, diverging and converging.

18. The apparatus of claim 14 , wherein said wavefront sensor element comprises a Hartmann plate.

19. The apparatus of claim 14 , wherein said wavefront sensor element comprises a one plate array.

20. The apparatus of claim 14 , wherein said wavefront sensor element comprises a crossed phase grating.

21. The apparatus of claim 20 , wherein said crossed phase grating comprises first portions having a first index of refraction at the wavelength of said first x-ray wavefront and said second x-ray wavefront and wherein said crossed phase grating comprises second portions having a second index of refraction at the wavelength of said first x-ray wavefront and said second x-ray wavefront, wherein said first index and said second index are different.

22. The apparatus of claim 14 , wherein said detector is selected from the group consisting of a CCD camera, a scintillator, at least one phosphor screen, at least one imaging plate, an x-ray film and amorphous selenium.

23. The apparatus of claim 14 , wherein said detector is placed at a distance d from said wavefront sensor element, wherein said distance is selected from the group consisting of (i) between 0 and d 2 /λ and (ii) between d 2 /λ and 2d 2 /λ, where λ is the wavelength of the x-rays of said x-ray wavefront and (iii) multiples of these distances.

24. The apparatus of claim 14 , further comprising means for calculating the intensity of said signal wavefront.

25. The apparatus of claim 14 , further comprising a backlighter positioned between said source and said wavefront sensor element, wherein said backlighter is selected from the group consisting of a spatially coherent backlighter or a periodic backlighter.

26. The apparatus of claim 14 , wherein said algorithm further comprises the steps of:

calculating 1 to n subsequent phase gradients between said signal wavefront and 1 to n reconstructed x-ray wavefronts, where n is the number of iterations;

simulating the propagation of said 1 to n reconstructed x-ray wavefronts back to said simulated screen to produce 1 to n propagated wavefronts;

adjusting said 1 to n propagated wavefronts with a percentage of said 1 to n subsequent phase gradients to produce a 1 to n adjusted wavefronts; and

simulating the propagation of said 1 to n adjusted wavefronts to said detector to produce a final reconstructed x-ray wavefront determined to have a desired phase gradient value.