Abstract
Traditionally, neutron diffraction at high pressure has been severely limited in pressure because low neutron flux required large sample volumes and therefore large volume presses. At the high-flux Spallation Neutron Source at the Oak Ridge National Laboratory, we have developed new, large-volume diamond anvil cells for neutron diffraction. The main features of these cells are multi-carat, single crystal chemical vapor deposition diamonds, very large diffraction apertures, and gas membranes to accommodate pressure stability, especially upon cooling. A new cell has been tested for diffraction up to 40 GPa with an unprecedented sample volume of ∼0.15 mm3. High quality spectra were obtained in 1 h for crystalline Ni and in ∼8 h for disordered glassy carbon. These new techniques will open the way for routine megabar neutron diffraction experiments.
| Original language | English |
|---|---|
| Article number | 083905 |
| Journal | Review of Scientific Instruments |
| Volume | 88 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 1 2017 |
Funding
We most gratefully acknowledge Tom B. Shiell and Jodie E. Bradby (Australian National University, Australia), Dougal G. McCulloch (RMIT University, Australia), and David K. McKenzie (University of Sydney, Australia) for their collaboration on the work concerning glassy carbon. We also gratefully acknowledge Stas V. Sinogeikin (HPCAT/Geophysical Laboratory) for the membranes used. We greatly appreciate the continuous support of Yarden Tsach of VFG technologies in developing large CVD diamond anvils. Work by R.B. was supported by the Energy Frontier Research in Extreme Environments (EFree) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES) under Award No. DE-SC0001057 and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy. This research was partially conduced at the SNAP beam-line of the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.