Inverse pole figure mapping of bulk crystalline grains in a polycrystalline steel plate by pulsed neutron Bragg-dip transmission imaging

Sato, Hirotaka*; Shiota, Yoshinori*; Morooka, Satoshi  ; Todaka, Yoshikazu*; Adachi, Nozomu*; Sadamatsu, Sunao*; Oikawa, Kenichi   ; Harada, Masahide   ; Zhang, S.*; Su, Y. H.  ; Kamiyama, Takashi*; Onuma, Masato*; Furusaka, Michihiro*; Shinohara, Takenao   ; Kiyanagi, Yoshiaki*

A new mapping procedure for polycrystals using neutron Bragg-dip transmission is presented. This is expected to be useful as a new materials characterization tool which can simultaneously map the crystallographic direction of grains parallel to the incident beam. The method potentially has a higher spatial resolution than neutron diffraction imaging. As a demonstration, a Bragg-dip neutron transmission experiment was conducted at J-PARC on beamline MLF BL10 NOBORU. A large-grained Si-steel plate was used. Since this specimen included multiple grains along the neutron beam transmission path, it was a challenging task for existing methods to analyze the direction of the crystal lattice of each grain. A new data-analysis method for Bragg-dip transmission measurements was developed based on database matching. As a result, the number of grains and their crystallographic direction along the neutron transmission path have been determined.