Tag Archives: turbomolecular pump

Turbomolecular Pump


Turbomolecular pump ( ‪#‎TMP‬ ) is a popular high vacuum pump, that is widely used in many vacuum systems (electron microscopes for example) as it is clean, fast and efficient for maintaining high vacuum over a long period of time. Inside the pump there are rotor blades that rotate with a speed up to 90 000 rotations per minute and stator blades that are stationary. If a gas molecule enters the pump then it is hit by the rotor blades that are tilted at a certain angle. The kinetic energy from the blade is transfered to the gas molecule and causes it to move down and hit a stator blade that is also tilted at a certain angle, causing the molecule to „bounce“ down, where it meets the next rotor blade. Eventually the gas molecules reach the bottom of the turbomolecular pump where they are removed with a backing pump (prevacuum pump). The turbomolecular pump usually also needs a pre-vacuum before it can work efficiently and this can be done with a pre-vacuum pump (for example a scroll compressor pump). Once the pressure is low enough, the ‪#‎turbomolecularpump‬ starts working and the rotation speed of the rotor blades is gradually increased.

Vacuum Systems and Technologies

Vacuum can be understood as space from where matter (for example air) has been removed. It naturally exists in outer space but for certain applications, like materials characterization techniques, it needs to be achieved artificially. The desired level of vacuum is obtained with the help of a suitable vacuum pump. For example low vacuum (low quality vacuum with higher pressure) can be generated with a diffusion pump, scroll compressor pump, rotary vane pump, diaphragm pump or a sorption pump. High vacuum (high quality vacuum with very low pressures) however, can be obtained with high vacuum pumps such as the turbomolecular pump, ion pump, titanium sublimation pump and cryopump. The level of vacuum is measured with devices called vacuum gauges (vacuum meters) like the thermocouple gauge, pirani gauge, penning ionization gauge and the quadrupole mass spectrometer (analyzer). The working principle of vacuum pumps and vacuum gauges is explained with 3D animations in the video lecture above.