Recent progress at RADEN, J-PARC

Kai, Tetsuya   ; Shinohara, Takenao   ; Tsuchikawa, Yusuke ; Su, Y. H.  ; Hasemi, Hiroyuki   ; Hayashida, Hirotoshi*; Parker, J. D.*; Matsumoto, Yoshihiro*; Kiyanagi, Yoshiaki*

The RADEN instrument at the Materials and Life Science Experimental Facility (MLF) of J-PARC is a pulsed neutron imaging instrument designed primarily for energy-resolved neutron imaging using the time-of-flight (TOF) method. By analyzing the energy dependence of neutron transmission through materials, advanced imaging techniques such as Bragg edge imaging for crystallographic analysis, resonance absorption imaging for nuclides and temperature distributions, and quantitative magnetic field imaging are made possible. To fully utilize these techniques, the development of dedicated analysis software has progressed alongside improvements in beamline hardware and detection systems. For Bragg edge imaging, we have released the GUI-RITS (Rietveld Imaging of Transmission Spectra) code, which provides a user-friendly interface and is executable on Windows OS. The code has been available for public download on the RADEN website since 2022. In the field of resonance absorption imaging, we have developed a new code called RAIM (Resonance Analysis code for neutron IMaging). RAIM reproduces the measured resonance absorption spectra by convolving the neutron cross-section, including resonances, with the pulse functions of the neutron beam. The software is designed to support quantitative analysis of nuclide distributions in complex materials and is scheduled for public release in 2025. In this presentation, we will report recent progress at RADEN, with a particular focus on the RAIM code development.