Advertisement

Abstract

The magnitude of the deadtime correction must be known in quantitative electron microprobe analyses since failure to apply the correction can lead to errors in the measured relative X-ray intensity ratio, k, which often are of the same magnitude as the precision in the determination of k; even greater errors will result when analyzing dilute alloys while using pure element standards. Heinrich, Vieth and Yakowitz [1] developed a simple method of determining the deadtime, τ, in the electron microprobe based on the model proposed by Ruark and Brammer [2] where the true counting rate, N t 0 , is given by N 0/(1-τN 0) and N 0 is the measured X-ray intensity from a pure element. Several investigators [3–7] have reported that τ is a function of the counting rate and becomes essentially zero below intensities varying from 4,000 to 14,000 cps [3–6]; in the Ruark [2] model, τ is independent of intensity. In an attempt to resolve this problem, a careful comparison was made between the current method described by Heinrich et al. [1], and the ratio method, which gives a range of zero deadtime, or negligible coincidence loss, described by Short [3], and Borile, Short and Tabock [4]. The deadtimes of the electronic components were measured, both individually and as complete counting systems, in an attempt to identify the deadtime source and to correlate X-ray (current and ratio methods) and electronic deadtimes.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Heinrich, K. F. J., D. Vieth, and H. Yakowitz: In: Advances in X-ray analysis, vol. 9 ( G. Mallett, M. Fay and W. Mueller, eds.), p. 208. New York: Plenum Press 1966.Google Scholar
  2. 2.
    Ruark, A., and F. E. Brammer: Phys. Rev. 52, 322 (1937).ADSCrossRefGoogle Scholar
  3. 3.
    Short, M. A.: Rev. Sci. Instr. 31, 618 (1960).ADSCrossRefGoogle Scholar
  4. 4.
    Borile, F., M. A. Short, and J. Tabock: In: Transactions of The Third National Conference on Electron Microprobe Analysis, Chicago, Illinois, July 31—August 2, 1968, paper No. 32.Google Scholar
  5. 5.
    Clayton, D. B.: Private communication concerning the activities of the Midlands Microanalysis Group 1967.Google Scholar
  6. 6.
    Beaman, D. R., and T. P. Schreiber. In: Transactions of The Third National Conference on Electron Microprobe Analysis, Chicago, Illinois, July 31—August 2, 1968, paper No. 49.Google Scholar
  7. 7.
    Wolf, R. C., and V. G. Macres: Stanford University, Stanford, California, Department of Materials Science, Report No. 63–18 (1963).Google Scholar
  8. 8.
    Spielberg, N.: In: Transactions of The Third National Conference on Electron Microprobe Analysis, Chicago, Illinois, July 31—August 2, 1968, paper No. 34.Google Scholar
  9. 9.
    Ziebold, T. O.: Anal. Chem. 39, 859 (1967).CrossRefGoogle Scholar
  10. 10.
    Borile, F.: Private communication.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1969

Authors and Affiliations

  • D. R. Beaman
    • 1
  • R. Lewis
    • 2
  • J. A. Isasi
    • 1
  1. 1.The Dow Chemical CompanyMidlandUSA
  2. 2.Consolidated Electrodynamics CorporationMonroviaUSA

Personalised recommendations