High-Resolution Analysis Using Bent Perfect Crystal in Powder Diffraction: Part II

0539686 - ÚJF 2021 RIV US eng J - Journal Article
Mikula, Pavol - Šaroun, Jan - Stammers, James H. - Em, V.
High-Resolution Analysis Using Bent Perfect Crystal in Powder Diffraction: Part II.
Journal of Surface Investigation-X-Ray Synchrotron and Neutron Techniques. Roč. 14, SUPPL 1 (2020), s. 151-155. ISSN 1027-4510
R&D Projects: GA MŠMT LM2015056; GA MŠMT LM2010011; GA MŠMT LM2015048
Research Infrastructure: Reactors LVR-15 and LR-0 II - 90120
Institutional support: RVO:61389005
Keywords : powder diffraction * focusing * bent crystal analyzer
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Method of publishing: Limited access
https://doi.org/10.1134/S1027451020070332

As a continuation of our recent studies of alpha-Fe(211) samples at a scattering angle of 2 theta(S)= 88 degrees (Part I), a three-axis setup using bent perfect crystal monochromator and several analyzers was tested in the diffraction study of polycrystalline alpha-Fe(110) pins with a diameter of 8 and 2 mm at a scattering angle of 2 theta(S)= 47.1 degrees. After realizing the focusing conditions in real and momentum space at a neutron wavelength of 0.162 nm, a high angular resolution was achieved up to FWHM(Delta d/d) = 1.4 x 10(-3)and FWHM(Delta d/d) = 2.5 x 10(-3)for alpha-Fe samples with a diameter of 2 and 8 mm, respectively. This resolution was obtained by using open beams, i.e., without Soller collimators within the used range of the curvatures of the analyzers. Such settings can be used in powder diffraction, namely, in studies of high-resolution residual stresses and/or analysis of diffraction profiles with a small difference in the lattice parameters or a small change due to the application of an external load.
Permanent Link: http://hdl.handle.net/11104/0317397