Neutron scattering measurements under pressure using a piston cylinder cell at chopper spectrometer AMATERAS

Kawamura, Seiko   ; Hattori, Takanori   ; Kambara, Wataru*

We have developed piston cylinder cells for the inelastic neutron scattering measurements at cold-neutron disk-chopper spectrometer, AMATERAS, in J-PARC. An Al alloy and a CuBe alloy were chosen as the cylinder material for experiments under pressures up to 0.5 and 1.5~GPa, respectively. A test measurement on a powder sample of a quantum spin system was performed using the Al alloy cell to evaluate the intensity of background and the - region where it appears. Further experiment on an organic radical system was performed using the CuBe cell for a feasibility test to observe phonon spectra and magnetic excitations. The CuBe cell was set to a bottom-loading He cryostat and cooled down to 0.3~K. These cells are now open for users' experiments. We have also conducted the quasielastic neutron scattering measurement on water under pressures up to 0.8 GPa using a hybrid piston-cylinder cell. Currently we are developing a compact radial collimator, which can be set to a sample rod of a top-loading closed-cycle refrigerator together with the piston cylinder cell.