Bragg diffraction optics in neutron diffractometry

Recent studies of highly oriented pyrolytic graphite and hybrid graphite-silicon monochromator systems

“…refs. [2][3][4]. Elastic bending permits to focus the reflected neutron beam and creates lattice deformations that increase the integrated reflectivity per unit volume.…”

Neutron Diffraction Studies of a Fully Asymmetric Diffraction Geometry of a Bent Perfect Crystal with the Output Beam Compression

“…An interest in fully asymmetric diffraction (FAD) geometry started in the past when elastically bent perfect crystals (BPC) have been found as a good alternative to conventional mosaic crystal monochromators or analyzers and several papers have been published on this topic [1][2][3][4][5][6][7][8][9][10]. In practice, the FAD geometry can be effectively studied in the case of BPC Si slabs, because the attenuation of thermal neutrons in Si is very low.…”

“…After that, bent perfect crystals in the FAD geometry were tested as thermal neutron analyzers and succesfully used in nondispersive double crystal settings for high resolution small * corresponding author; e-mail: mikula@ujf.cas.cz angle neutron scattering (SANS) diffractometers [6][7][8]. A unique proposal of a possible use of FAD BPC Si slab as a high resolution TOF analyzer of thermal neutrons was also succesfully tested [9,10]. Finally, it should be mentioned that in the paper [11] the optics of double bent crystal rocking curves is theoretically described for symmetric and asymmetric diffraction geometries of the individual crystal slabs in a general mutual setting.…”

Neutron diffraction studies of a double-crystal (+n,–m) setting containing a fully asymmetric diffraction geometry of a bent perfect crystal with output beam expansion

“…It should be pointed out that other attempts were also carried out by employing a FAD BPC Si slab as an analyser of a beam diffracted by a polycrystalline sample in experiments for strain/stress determination . Finally, a unique proposal of a possible use of a FAD BPC Si slab with output beam expansion (OBE) geometry as a high-resolution time-of-flight (TOF) analyser of thermal neutrons was also succesfully tested (Mikula et al, 2003(Mikula et al, , 2004. Our recent attention has been focused on other FAD properties of the BPC slab, mainly in combination with another BPC slab of a different d spacing, in the so-called parallel (+n,Àm) double-crystal setting, which could provide further application possibilities.…”