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Specimen displacement error in focusing systems

Published online by Cambridge University Press:  10 January 2013

Z. Sperling
Affiliation:
2085 W 5th Avenue, #304, Vancouver, V6J 1P8 British Columbia, Canada

Abstract

The error is investigated which results from the employment of tangential approximation in the calculation of line shift caused by specimen displacement from the recording circle in focusing systems (Guinier, Seemann–Bohlin). After an exact expression has been deduced and compared with the approximate formula in a numerical example, it is concluded that the error caused by the approximate formula may be important only in exceptional cases. The deduced exact formula is also compared with that given by Rafaja and Valvoda [Powder Diffr. 6, 200–203 (1991)] with the conclusion that both formulas are mathematically equivalent and complementary with respect to the theoretical and measured values of the diffraction angle 2θ.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1995

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References

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