Advertisement

Note on “Superlarge” Structures and Their Phase Problem

  • David Sayre
Chapter
Part of the NATO ASI Series book series (NSSB, volume 274)

Abstract

Work carried out over the last few years1 suggests that it may be possible to extend x-ray diffraction techniques to the determination of structures of non-crystalline specimens of microti size, such as single small biological cells. Work to date has concentrated on showing that the diffraction from microscopic non-crystalline objects, while extremely faint, can be observed by employing high-intensity synchrotron x-ray sources, shifting to longer wavelengths, and increasing the coherence of the radiation. Assuming undulator radiation with high spatial coherence it is mainly the temporal coherence of the radiation which is at issue; assuming radiation of monochromaticity M the maximum resolution to which diffraction from a specimen of diameter a will normally extend is of the order of a/M. Using radiation with M=150 and individual cells of Minutocellus polymorphus with a=3µm we have observed pattern in 18A radiation to approximately 200A resolution, in good agreement with the above. Fig. 1 shows a portion of such a pattern. In certain special cases we have observed diffraction to 70A resolution.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    D. Sayre, W.B. Yun, and J. Kirz, Experimental observation of diffraction patterns from micro-specimens, in: “X-Ray Microscopy II”, Springer Series in Optical Sciences Vol 56 (1988).CrossRefGoogle Scholar
  2. 2.
    D. Sayre, Some implications of a theorem due to Shannon, Acta Cryst. 5:843 (1952).CrossRefGoogle Scholar
  3. 3.
    M.H. Hayes, The reconstruction of a multidimensional sequence from the phase or magnitude of its Fourier transform, IEEE ASSP-30:140 (1982).CrossRefGoogle Scholar
  4. 4.
    R.H.T. Bates, Fourier phase problems are uniquely solvable in more than one dimension. I: Underlying theory, Optik 61:247 (1982).Google Scholar
  5. 5.
    J. Fienup and C. Rushforth, eds., J.Opt.Soc.Am. A4:102–304 (1987).Google Scholar
  6. 6.
    G. Bricogne, A Bayesian statistical theory of the phase problem. I. A multichannel maximum-entropy formalism for constructing generalized joint probability distributions of structure factors, Acta Cryst A44:517 (1988).CrossRefGoogle Scholar
  7. 7.
    S. Aoki and S. Ķikuta, X-ray holographic microscopy, Jpn.J.App.Phys. 13:1385 (1974).CrossRefGoogle Scholar
  8. 8.
    C. Jacobsen, J. Kirz, M. Howelis, K. McQuaid, S. Rothman, R. Feder, and D. Sayre, Progress in high-resolution, x-ray holographic microscopy, in: “X-Ray Microscopy II”, Springer Series in Optical Sciences Vol 56 (1988).Google Scholar
  9. 9.
    D. Joyeux, S. Lowenthal, F. Polack, and A. Bernstein, “X-ray microscopy by holography at LURE”, ibid., p. 246 (1988).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • David Sayre
    • 1
  1. 1.IBM Research CenterYorktown HeightsUSA

Personalised recommendations