Cascade: An automatic single-crystal X-ray diffractometer

Abstract

An automatic system is described for the measurement of intensities of X-ray reflections from single crystals. It is controlled by a programmable plugboard and punched paper tape output from an IBM 1620 computer. The goniometer used is the G.E. single crystal orienter. A circuit is provided which maximizes the counting rate before the intensity is measured.

X-Ray Diffraction

“…The new NBS publication of this series is designated as Monograph 25 (93), superseding Circular 539, Volumes 1 through 10. Two sections of the new Monograph 25 have been published. The first section contains a brief account of the arrangement used in reporting the experimental data plus conversion factors for comparison of peak heights and integrated intensities and a cumulative index to the 10 volumes of Circular 539.…”

Analogue and digital single-crystal diffractometers

“…Diffractometers with appropriate order codes have been described by Abrahams (1962), Cowan, Macintyre & Werkema (1963), Arndt & Willis (1963) and Arndt (1963b). Such instruments, even when used off-line, have a much greater versatility than fixed-program installations.…”

“…The convergent beam method demands a higher setting accuracy than do moving crystal methods; it may be necessary to resort to special peak-searching techniques when this method is applied to small crystals (Cowan, Macintyre & Werkema, 1963).…”

“…The only variation in technique consists in keeping the crystal stationary during the measurement of the reflexion, integration being supplied by illuminating the crystal by convergent radiation from an extended uniform source. (Cochran, 1950;Furnas & Harker, 1955;Cowan, Macintyre & Werkema, 1963). It is in the setting of the crystal and detector that three basic approaches are possible.…”