Wednesday, April 11, 2012

Maximum pressure achieved on SNAP increases again!

In collaboration with the instrument staff, members of the Carnegie IDT team (Guthrie, Boehler, Li, Machida) have increased the maximum pressure for measuring structural refinement-quality data to 57 GPa. At this (unofficial) record-breaking pressure Bragg intensities were clearly visible down to ~0.75 Å and full structural refinements have conducted.

On increasing the pressure further, there was a failure of the carbide seat (at an estimated 60 GPa). In ongoing developments, these seats will be replaced with a sintered diamond variant, with the aim of extending the maximum pressure further into the 100 GPa range.  

The figure shows a Rietveld fit to a typical data set from a test sample of D2O at around 3 GPa measured on SNAP.