A powder diffractometer for a synchrotron source

A design is given for a powder diffractometer on a synchrotron source. A reasonable balance between resolution and luminosity is achieved by making the effective mosaic spread parameters of the monochromator and analyser crystal equal to the vertical divergence of the synchrotron beam. A monochromator with a Bragg angle of 60° should be used. Care is necessary in preparing specimens for data collection to avoid the hazards of particle-size broadening on one hand and extinction on the other. The conclusions are compared with recent experimental work.