Influence of beam divergence on pseudo-strain induced in time-of-flight neutron diffraction

Suzuki, Hiroshi  ; Harjo, S.   ; Abe, Jun*; Akita, Koichi

Effects of beam divergence on pseudo-strains observed in time-of-flight (TOF) neutron diffraction, that overlapped with the neutron attenuation effect and the surface-effect were investigated. The through-surface strain scanning on an annealed steel plate was performed in different instrument resolutions by controlling the incident beam divergence. Typical pseudo-strain distributions were observed, but they showed different trend according to the beam divergence. Furthermore, it was demonstrated that the pseudo-strains induced in the strain scanning of coarse grain materials can be suppressed by controlling the incident beam divergence. Therefore, the incident beam divergence must be carefully considered to reduce pseudo-strains in time-of-flight neutron diffractometry.