Pumping Systems
The three types of pump systems: positive displacement, momentum transfer, and entrapment.
Positive displacement: Uses a mechanism to repeatedly expand a cavity, allow gases to flow in from the chamber, seal off the cavity, and exhaust it to the atmosphere. Ex: rotary and screw pumps
Rotary: 
Screw: 
Momentum transfer: Uses high speed jets of dense fluid or high speed rotating blades to knock gas molecules out of the chamber. Ex: Diffusion and turbo molecular
Diffusion: 
Turbo molecular: 
Entrapment: capture gases in a solid or adsorbed state. Ex: Ion and sorption pumps
Ion: 
