Abstract
This paper is a technical report of synthetic phosphate lubricants, Cellulube 220 and 300, in certain aspects of their use as diffusion pump fluids. The vapour pressures, the ultimate pressures, the stabilities, and the chemical properties have been examined for these fluids. The ultimate pressure obtained experimentally by using the fluid in the metal pump only with' an unrefrigerated chevron baffle is 1.0 × 10-8Torr or lower. It is presumed that the chemical species is not tricresyl phosphate, but is probably trixylenyl phosphate, although it is written to be triaryl phosphate in the commercial literature of the manufacturer.
