Working Principle and Structure of Cryopump
The working principle of the cryopump is to use the physical adsorption of gas on the ultra-low temperature surface to achieve the effect of exhaust. It is an effective and fast method to obtain a clean vacuum.
The cryopump can reach extremely high vacuum (10-11 Pa), which has the advantages of fast exhaust speed, no oil, and unlimited installation direction.
A shield and a baffle are set on the first stage of the cryopump to maintain the temperature at 80K. The secondary cold stage is maintained at 15K with a low temperature cover and activated carbon adsorbent.
Water vapor is solidified on the 80K shield and 80K baffle; nitrogen, oxygen and argon are solidified on the 15K low temperature cover; hydrogen, helium and neon are adsorbed on the adsorbent inside the 15K low temperature cover. The cryopump can exhaust all gases, but if too much gas is adsorbed, the exhaust speed decreases. At this time, the cryopump needs to be heated to release the adsorbed gas and then reused.
