Recent developments and current status of high-pressure neutron diffractometer PLANET in J-PARC

Hattori, Takanori   ; Sano, Asami   ; Machida, Shinichi*; Abe, Jun*; Funakoshi, Kenichi*; Arima, Hiroshi*

The first domestic high-pressure powder neutron diffractometer PLANET celebrated five years since its operation started. Here, we will introduce the current status and subsequent progress. Expansion of measurable PT region: In the experiments using a 6-axis press, in-situ observation at 14 GPa, 1800 K became possible by increasing the anvil strength by shrink fitting and replacing a graphite with a TiC + AlO heater. In experiments using the Paris Edinburgh Press (PE press), by reducing the anvil top to 2.5 mm in diameter, experiments at 30 GPa are possible. Improvement of measurement data quality: when using a PE press, samples are normally pressurized together with liquid pressure medium to avoid peak broadening. However, above 10 GPa, the medium solidifies and the peaks are broadened. To fix this problem, a system capable of heating the sample up to 100C was designed and now we can obtain sharp diffraction peaks up to 20 GPa. New measurement method: In order to obtain macroscale information of samples under high PT condition, we attempted neutron radiograph. By using a compact neutron camera, we can place a camera close to the sample and obtain high resolution images.