Advanced neutron diffraction techniques for strain measurements in polycrystalline materials

Three unique high resolution experimental arrangements for nondestructive strain measurements which are based on neutron Bragg diffraction optics with cylindrically bent perfect crystals are reviewed. Using focusing in momentum and real space these techniques yield Δd/d (d-lattice spacing) resolution of 10-4 - 10-3 and considerably higher luminosity in comparison with the current dedicated instruments. They permit measurements not only macrostrain components resulting in angular shifts of diffraction peaks but also of microstrains by means of profile-broadening analysis