## 5 Conclusions  
In this study, the single Bragg-dip profile-fitting analysis method was developed. This method can evaluate and visualize detailed crystalline information of single crystals and oligocrystals. This method was applied to experimental data of position-dependent Bragg-dip neutron transmission spectra measured from an oligocrystal material to confirm the effectiveness. In the analysis, the Gaussian function was fitted to an individual Bragg-dip profile on the neutron transmission spectrum. By using this method, the wavelength where Bragg-dip appears, the width of Bragg-dip and the integrated intensity of Bragg-dip were deduced at each pixel of the neutron TOF-imaging detector.  
From the results of imaging of the Bragg-dip wavelengths, the slight changes in the pattern of Bragg-dip wavelengths and the slight change in the crystal orientation in the crystalline grain, about 0.4\({}^{\circ}\), could be observed. From the results of imaging the broadening of Bragg-dip, a mosaic block could be observed in the crystalline grain. Moreover, another crystalline grain, whose crystal orientation was different by about 0.9\({}^{\circ}\), could be observed in this crystalline grain through the observation of the Bragg-dip split. In the results of imaging of the integrated intensity of Bragg-dip, the integrated intensity became larger at the region where the aforementioned mosaic block existed. This is because the extinction effect reduced. This was caused by the decrease in the crystallite size. This means some mosaic blocks exist along the neutron transmission path. Thus, imaging of the integrated intensity of Bragg-dip also shows the existence of the mosaic block as well as imaging of the width of Bragg-dip. Furthermore, the change in the crystal thickness could also be visualized. Thus, the fluctuation of the crystal orientation and the existence of mosaic blocks in a crystalline grain could be observed in the real-space image. This crystalline information could not be observed in the previous method.  
As explained above, this method can visualize detailed crystalline information which has not been visualized by previous analysis methods. The significant feature of the proposed method is the simplicity of the data analysis. By combining this method with the full pattern-fitting analysis [18] and the wavelength pattern analysis [19], more detailed crystalline information evaluation of single crystals and oligocrystals will be realized in the imaging mode.  
Conceptualization, H.S., N.A., S.M., Y.T. and T.K.; methodology, Y.S., H.S., S.M. and T.K.; software, Y.S. and H.S.; validation, Y.S., H.S., N.A., S.M., Y.T. and T.K.; formal analysis, Y.S. and H.S.; investigation, Y.S., H.S., N.A., S.M., Y.T. and T.K.; resources, H.S., S.M., Y.T. and T.K.; data curation, Y.S. and H.S.; writing--original draft preparation, Y.S.; writing--review and editing, H.S., N.A., S.M., Y.T. and T.K.; visualization, Y.S. and H.S.; supervision, H.S., N.A., S.M., Y.T. and T.K.; project administration, H.S., S.M., Y.T. and T.K.; funding acquisition, H.S., S.M., Y.T. and T.K. All authors have read and agreed to the published version of the manuscript.  
This research was funded by JSPS KAKENHI Grant Number 16K20876.  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
The authors would like to thank [PERSON] (Metal Technology Co., Ltd.), [PERSON] (J-PARC), [PERSON] (J-PARC), [PERSON] (J-PARC) and [PERSON] (CROSS) for experimental assistance at J-PARC MLF BL10 NOBORU. The neutron experiment at J-PARC MLF BL10 NOBORU was performed under a user program (proposal No. 2014P0601). This work was partially supported by the ISIJ research group \"steel microstructure analysis using compact neutron sources\".  
The author declares no conflict of interest.