Vacuum particle generation and the nucleation phenomena during pumpdownJournal of Vacuum Science & Technology A (1990)
This paper explores the source of an unexpectedly large number of particles found while examining the rough pumping cycles of a vacuum system. It is proposed that these particles are generated through nucleation of moisture onto fine particles during pumpdown, and that turbulence enhances this process. A brief discussion about the particle monitor used for data acquisition and a review of previous experimental results on the dependency of particle generation on turbulence is included. The body of the paper contains experimental results supporting the nucleation hypothesis, and a discussion on the effects and prevention of particle nucleation. The experimental results include a comparison of particle generation for two gases of similar original particle content but different humidity levels, reduction of particle count using a molecular sieve to remove the moisture in the chamber, and a systematic change of the relative humidity (by adding or removing moisture) in the chamber.
Citation InformationDegang Chen and Susan Hackwood. "Vacuum particle generation and the nucleation phenomena during pumpdown" Journal of Vacuum Science & Technology A Vol. 8 Iss. 2 (1990) p. 933 - 940
Available at: http://works.bepress.com/degang-chen/2/