Diffusion Pumps
The Diffusion Pumps are the back up instruments for pumping the high volume at a very very low pressure (High Vacuum) area the instrument picks up air from the High Vacuum Area and delivers it to the suction of High Vacuum Pump at a elevated pressure which a high vacuum pump can handled. The vacuum reached is 10-7 Millibar at the suction side of the Diffusion Pump.
The vaporisation and condensation of the specialised oil results in pushing out the low pressure air/vapour through the exhaust ports.