Automatic Neutron Diffractometer for Three-Dimensional Structure-Factor Determination

Abstract

This fully automatic single‐crystal diffractometer employs the Eulerian hoop geometry. It is under punchedtape control and the three independent shafts are set simultaneously for each reflection to an accuracy of 0.03° using a moiré fringe positioning system. The reflection is then measured by moving the crystal in steps across the reflecting position. The time on each step is variable, being determined by a monitoring counter, and the number of steps is under program control. Results are both printed in plain language and punched on a paper tape, ready for direct processing in a computer.