title: Pressure/temperature fluid cell apparatus for the neutron powder diffractometer instrument: probing atomic structure in situ.
abstract: This contribution describes a new local structure compatible gas/liquid cell apparatus for probing disordered materials at high pressures and variable temperatures in the Neutron Powder Diffraction instrument at the Lujan Neutron Scattering Center, Los Alamos National Laboratory. The new sample environment offers choices for sample canister thickness and canister material type. Finite element modeling is utilized to establish maximum allowable working pressures of 414 MPa at 15 K and 121 MPa at 600 K. High quality atomic pair distribution function data extraction and modeling have been demonstrated for a calibration standard (Si powder) and for supercritical and subcritical CO2 measurements. The new sample environment was designed to specifically target experimental studies of the local atomic structures involved in geologic CO2 sequestration, but will be equally applicable to a wide variety of energy applications, including sorption of fluids on nano/meso-porous solids, clathrate hydrate formation, catalysis, carbon capture, and H2 and natural gas uptake/storage.
authors.affiliation: Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Hsiu-Wen
authors.initials: HW
authors.lastname: Wang
authors.affiliation: Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Victor R
authors.initials: VR
authors.lastname: Fanelli
authors.affiliation: Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Helmut M
authors.initials: HM
authors.lastname: Reiche
authors.affiliation: Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Larson
authors.affiliation: Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Taylor
authors.affiliation: Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Hongwu
authors.initials: H
authors.lastname: Xu
authors.affiliation: High Pressure Science and Engineering Center, Department of Physics and Astronomy, The University of Nevada, Las Vegas, Nevada 89154, USA and National Lab for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Joan
authors.initials: J
authors.lastname: Siewenie
authors.affiliation: Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Katharine
authors.initials: K
authors.lastname: Page