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

A unique resolution function of angular-dispersive synchrotron radiation po wder diffractometers, properly parameterized to be valid for any multicryst al variant of this instrument, has been derived paying special attention to the absolute correctness of the formulae by avoiding any unknown proportio nality factors. Moreover, the concept of experimental performance criterion has been proposed in an attempt to introduce a kind of 'worth-scale' for t he results of measurements performed with a certain instrumental configurat ion. Both entities were used in computer simulations to determine the most convenient configuration of instrumental parameters that, apart from the fu lfilment of the experiment seal, 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 volum es were considered. The results offer reliable information that may be usef ul for designing diffractometers as well as for conducting experiments.