Optimization of resolution–intensity balance in angular-dispersive powder diffractometry at a synchrotron radiation source

Abstract

A unique resolution function of angular-dispersive synchrotron radiation powder diffractometers, properly parameterized to be valid for any multicrystal variant of this instrument, has been derived paying special attention to the absolute correctness of the formulae by avoiding any unknown proportionality factors. Moreover, the concept of experimental performance criterion has been proposed in an attempt to introduce a kind of `worth-scale' for the results of measurements performed with a certain instrumental configuration. Both entities were used in computer simulations to determine the most convenient configuration of instrumental parameters that, apart from the fulfilment of the experiment goal, ensure an adequate counting rate. Several case studies using different instrumental layouts, different single-crystal monochromators and samples of different low symmetries and unit-cell volumes were considered. The results offer reliable information that may be useful for designing diffractometers as well as for conducting experiments.