Abstract
Two unconventional high-resolution monochromator performances using Bragg diffraction optics and based on cylindrically bent perfect crystals which have been recently tested with the aim of their efficient employment in strain diffractometers are reviewed. It has been found that the optimized diffractometer arrangements employing such monochromators provide good luminosity and a high resolution (FWHM of the instrumental Δd/d - profile can be about 2.7x10^<-3> in the double-crystal case or less than 8x10^<-4> in the Umweganregung case) in the vicinity of usually used 2θ_S ≈ 90°. Presented results demonstrate their experimental abilities for powder diffraction, namely for residual strain/stress measurements. Due to the unique resolution and good luminosity achieved, besides the macrostrain scanning, the presented performances also qualified for possible microstrain/stress studies by an analysis of the diffraction profiles.