A heatable large volume pressure cell for neutron powder diffraction: The Kiel-Berlin Cell II

The construction principles of a new heatable large volume high-pressure ce ll for neutron powder diffraction, the Kiel-Berlin Cell II, are presented. The basic design is of the piston/cylinder type. The cell is designed to op erate up to pressures of 3.5 GPa and temperatures above 800 K. First tests showed the mechanical stability of the cell to be ensured up to the corresp onding necessary sample load of 50 tons and a prestress of 110 tons. The ce ll is intended for use at reactor-based neutron sources. The use of a large sample (1.5 cm(3)) allows rapid data collection. There are no major geomet rical restrictions in the scattering plane. The projected temperature could be reached simultaneously to the application of pressure. First neutron ex periments revealed a good signal-to-noise ratio of the diffracted neutrons. For the present layout of the Ti/Zr pressure cylinders and upper stability limit of 1.2 GPa was determined. (C) 1999 American Institute of Physics. [ S0034-6748(99)01602-0].