Neutral Molecule Desorption from SS(304) and A1(6061) Due to Particle Bombardments

The pressure in both electron and proton storage rings is dependent on the particle wall bombardment molecular desorption rates due in one case (proton storage rings) to ~ keV ions while in the other to ~ 100 eV electrons. Also in order to minimize secondary electron amplification effects in both types of machines the secondary electron emission coefficient should be as low as possible. The above quantities have been measured on A1(6061) and SS(304) materials having had various treatments including a sputter deposition of Ti and TiN in the case of A1. The results indicate for both electron and proton storage rings that SS(304) materials properly prepared have particular advantages over A1 considering both molecular desorption yields and secondary electron emission effects.