Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-06-24T10:35:07.668Z Has data issue: false hasContentIssue false
  • English
  • Français

The Effect of Grating Blaze Angle on the Diffraction Efficiency of Ultrasoft X-Ray Radiation

Published online by Cambridge University Press:  06 March 2019

James B. Nicholson ,
C. Frank Mooney  and
Gordon L. Griffin
James B. Nicholson
Affiliation:
Hasler Research Center Applied Research Laboratories, Inc. Goleta, California
C. Frank Mooney
Affiliation:
Bausch and Lomb, Inc. Rochester, New York
Gordon L. Griffin
Affiliation:
Bausch and Lomb, Inc. Rochester, New York
Get access

Abstract

Spectrum analysis in the ultrasoft X-ray region is complicated by the fact that this radiation is almost totally absorbed in any medium. This has necessitated spectrometer components which minimize this effect. Nondispersive and total reflection techniques, though high in speed, lack good resolution and in the case of the latter, are usually restricted to analysis of elements differing by at least three atomic numbers.

Diffracting media which have proven successful are the long-chain organic crystals and gratings at grazing incidence. The grating is superior to the organic crystal concerning resolution and dispersion and has proven to be comparable arid in some cases better for peak intensity and line-to-background ratios.

Lightly-ruled gratings have been used for many years, but little attention has been given the blazed grating until recently. Since the critical angle of total reflection for a given material is wavelength-dependent, it may be utilized to discriminate against shorter wavelengths and thus improve line-to-background ratios. The optimum conditions for sensitivity, then, would be to relate the input angle to the blaze angle and vary the input angle as a function of wavelength, thereby maximizing the line intensity or the line-to-backgrourid ratio as required.

Several gratings with varying blaze angles and surface finishes are evaluated with O Kα (23.7Å) and C Kα (44Å) radiation.

The importance of groove profile is emphasized by comparing the profile as determined by the electron microscope with the experimental evidence. The variation of diffraction efficiency with wavelength and input angle is then considered theoretically and compared with experimental results.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 8: Thirteenth Annual Conference on Applications of X-ray Analysis, August 12-14, 1964 , 1964 , pp. 301 - 314
Copyright
Copyright © International Centre for Diffraction Data 1964

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Dolby, R. M., “Some Methods for Analysing Unresolved Proportional Counter Curves of X-Ray Line Spectra,” Proc. Phys. Soc, (London) 73:81–94, 1959.Google Scholar
2. Franks, A. and Baybrook, R. F., “Analysis of the Lighter Elements by Total Reflectioo of Their Characteristic X-Ray Wavelengths,” J. Appl. Phys. 10:190–191, 1959.Google Scholar
3. Nicholson, J. B. and Wittry, D. B., “A Comparison of the Performance of Gratings and Crystals in the 20-115 A Region,” in Advances in X-Ray Analysis, Vol, 7, University of Denver, Plenum Press, New York, 1963, pp. 497–511.Google Scholar
4. HoUiday, J. E., “A Soft X-Ray Spectrometer Using a Flow Proportional Counter,” Rev. Sci. Instr. 31(8):891, 1960.Google Scholar
5. Stenstrom, W., dissertation, Lund, 1919.Google Scholar
6. Compton, A. H., “The Total Reflection of X-Rays,” Phil. Mag. 45:1121-31, 1923.Google Scholar
7. Lukirskii, A. P., Sovinov, E. P., Ershov, O. A., and Shepelev, Yu. F., “Reflection Coefficients of Radiation in the Wavelength Range from 23.6 to 113 Å for a Number of Elements and Substances,” and “Determination of the Refractive Index and Absorption Coefficient,” Optika i Spektroskvpiya 16(2):310–319, 1964.Google Scholar
8. Ibid. Google Scholar
9. Thibaud, J., Helvet. Phys. Act. 2: 271, 1929.Google Scholar
10. Prins, J. A., “X-Ray Diffraction by Plane Gratings,” Nature 124: 370, 1929.Google Scholar
11. Dershem, E., “The Reflection of the Kα Line of Carbon from Glass,” Phys. Rev. 34:1015–1020, 1929.Google Scholar
12. Dershem, E. and Schein, M., “The Reflection of the Kα Line of Carbon from Quartz and its Relation to the Index of Refraction and Absorption Coefficient,” Phys. Rev. 37:1246–1251, 1931.Google Scholar
13. Dershem, E. and Schein, M., “The Absorption and Reflection of Long-Wave Rontgen Rays,” Zeit. f. Phys. 75:395–414, 1932.Google Scholar
14. Meyer, C. F., The Diffraction of Light, X-Rays, and Material Particles, Univ. of Chicago Press, Chicago, Ill., p. 345, 1934.Google Scholar
15. Holliday, J. E., Hand Book of X-Rays, McGraw-Hill Book Company, New York, 1964, in press.Google Scholar
16. Henke, B. L. and Miller, J. C., “Ultrasoft X-Ray Interaction Coefficients,” AFOSR TN-59-895, Washington 25, D.C., Contract #AF 49(638)-394.Google Scholar
17. Griffin, G. L., Vetter, M. B., and Mooney, C. F., “Technique for Measuring Profiles of Microscopic Grooves,” to be presented at Electron Microscope Society, October 13, 1964.Google Scholar
18. Nicholson, J. B. and Wittry, D. B., “A Comparison of the Performance of Gratings and Crystals in the 20-115 A Region,” in Advances in X-Ray Analysis, Vol. 7, University of Denver, Plenum Press, New York, 1963, pp. 497–511.Google Scholar