Bragg-edge transmission imaging of strain and microstructure using a pulsed neutron source

The residual strain and the total cross-section in Fe plate was investigated by a Bragg-edge transmission method. The experiments were performed at the position of the time-of-flight diffractometer at KENS, Sirius. The (Δd/d) reached about 0.1%. The high counting rate and high efficiency pixel type 2d-detector with 8x8 pixels was used. The spatial resolution is about 2.1 mm. We clearly observed the image of the change on Bragg-edge shapes and the strain distribution. The total cross-section around the bending points was larger than other areas but there was no change in the Bragg-edge positions, which would correspond to the change of the microstructure. We obtained the image of residual strain at several points. The values of the residual strain at several lattice planes, ε110, ε200 and ε211, are -263 to 1707 με, -612 to 1665 με and -1205 to 327 με, respectively. It is indicated that the residual strain measurement by the Bragg-edge transmission is not inferior to the high-resolution Bragg diffraction.