The Diacell® LeverDAC-Mega is for work to the highest pressures diamond can withstand. Carefully selected diamonds mounted on high-quality tungsten carbide support plates are set within a piston-cylinder assembly manufactured to very high specification. The mechanical stability essential for generating megabar (> 100 GPa) pressures is ensured by use of a piston which is long compared with its diameter.
The lower anvil plate is provided with lateral adjustments to permit the faces of the two anvil working faces to be brought into coincidence. The upper anvil is mounted upon a hemisphere lapped into the cup-end of the piston. Three screws allow the tilt of the hemisphere to be altered to bring the anvil faces exactly into parallelism with each other.
All adjustments necessary for alignment may be made under a standard metallurgical microscope. The diamond anvils may be accessed by four 8 mm diameter lateral holes through which electrical and other lead-ins may be fed. The cell is shipped aligned and ready for use.
Pressure is generated by compression of a stack of very hard disc springs which, in turn, operate a lever and plate, the latter bearing directly upon the rear of the anvil piston. Two 6 mm diameter holes are provided in the base for mounting: other fixing arrangements may be specified when ordering.
Provision is made for fixing the lower presser plate to the central cylinder with four bolts. Once pressure has been applied to the sample, these bolts may be tightened, the cell disassembled, and the central insert mounted in an experimental enclosure. Several inserts may thus be used with one body, and the arrangement also facilitates cryogenic loading.