High Pressure Measurements
Diamond Anvil Cells
Contact the beamline team if interested in a high-pressure diamond anvil cell (DAC) experiment.
The beamline will provide a linear stage for you to mount your bracket and DAC. The mounting bracket will need to be able to hold the cell securely without rotation and movement, so alignment throughout the experiment is maintained. Our beam is 0.8 mm x 0.8 mm and will be cut to 0.2 x 0.2 mm to avoid hitting the gasket. An energy of 21 keV is used so the beam is able to penetrate through the diamonds and sample. User groups need to provide the mounting brackets and DACs themselves.
See the linear stage engineering drawing (Huber model 5101.20) below for the screw holes to attach your mounting bracket.
Include a photo of your cell and mounting bracket dimensions in the proposal otherwise it may be assessed as technically infeasible. Also outline your experience in DAC high pressure experiments so we can determine how much training is required. We highly recommend collaborating with experienced DAC users if you are a new user of this setup.
The beamline has an optical system to optically measure the pressure based on the fluorescence of ruby and a gasket drill press for users. Ruby balls are added into the cell and their florescence is used to determine the pressure inside the cell. These will fluoresce as red so those that are colour blind will not be able to see them.
High Pressure Capillary Measurements
Capillaries can be pressurised during in situ measurements. It is mandatory that thick wall (0.02-0.05 mm) quartz capillaries are used for experiments where internal capillary pressures >5 bar are expected. These capillaries can be specially ordered from Hilgenberg.
Pressure range | Quartz capillary wall thickness requirement |
|---|---|
5 - 10 bar | 0.02 mm |
10 - 20 bar | 0.05 mm |
For all high pressure, capillary experiments, the maximum pressure allowed is 2 MPa (20 bar). Higher pressures are possible by prior agreement with beamline staff, however sapphire capillaries will be required and the upper pressure limit is capped.
Note: Any high-pressure gas experiments above 5 bar with inert gases requires 2 people present at the beamline at all times to monitor the capillary and ensure that breakages are detected as soon as they occur.