A new belt-type apparatus for neutron-based rheological measurements at gigapascal pressures

• Published in: High pressure research Vol. 25; no. 2; pp. 107 - 118
• Main Authors: Dobson, David P., Mecklenburgh, Julian, Alfe, Dario, Wood, Ian G., Daymond, Mark R.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.06.2005
• Subjects: High pressure; High temperature; Rheology; TOF neutron diffraction
• ISSN: 0895-7959; 1477-2299
• DOI: 10.1080/08957950500143500

We have developed a new solid-media apparatus for performing rheological investigations at multi-gigapascal pressures. The pressure cell consists of a simple belt design and fits in a modified 250 tonne Paris-Edinburgh press. Elastic strains are measured by neutron diffraction, on the ENGIN-X experimental station at ISIS. Stresses are estimated from the measured strains in combination with published values of the elastic moduli. As an exemplair of the method, we present data from initial deformation experiments on pyrope garnet at 1.5 GPa and 873 K. Data collection times are as short as 60 min and the elastic strain resolution is better than 10 −4 . We anticipate, however, that by interrupted testing, strain rates as low as 10 −9 /s, or lower, will be measurable.