turbo-molecular pump

A mechanical, dry vacuum pump that does not use oil. In the turbo-molecular pump, a high-speed rotor provides momenta to residual gas molecules in the pumping direction and the gas molecules are pumped. A rotary pump or the other pump is required to evacuate the backside of the turbo-molecular pump. The pump operates at low to high vacuum. The working pressure is 10^-1 to 10^-8 Pa. Recently, problems of sound noises and mechanical vibrations have been solved. Any gas can be pumped by this pump. Unlike the diffusion pump, the pump is suitable for pumping water H₂O. Thus, the pump is sometimes used for a biological TEM. The price of the pump is higher than the ion pump. Care has to be paid for mechanical failure.