JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - UNPB AU - Audi, M.A. ED - Zhang, Tianjue ED - Schaa, Volker R.W. ED - An, Shizhong ED - Kiselev, Daniela ED - Liu, Yuntao ED - Li, Pengzhan TI - Ion Pumps for UHV Systems, Cyclotrons Synchrotrons & Particle Accelerators J2 - Proc. of CYCLOTRONS2022, Beijing, China, 05-09 December 2022 CY - Beijing, China T2 - International Conference on Cyclotrons and their Applications T3 - 23 LA - english AB - From the invention by Varian Associates in 1957, Ion pump became the main choice for UHV systems, cyclotrons, synchrotron and particle accelerators, due to reasons like ’closed pump’, ’no moving parts’, ’no lubricant’, ’can withstand air inrush or improper use’. There are different types of Ion pumps, normal Diode Ion Pump has very limited noble gases pumping, both speed and capacity, has only 5% of air pumping speed for argon, while Noble Diode Ion pump can reach to 15%-20%, and StarCell Ion Pump has an argon pumping speed up to 35%-40% of air pumping speed. In order to reach UHV, outgassing / cleanliness is even more important than pumping speed, the ion pump element must be the cleanest surface exposed to vacuum, because its outgassing is due to both thermal and bombardment induced effect, the cathode surface will eventually be removed (sputtered). Therefore, not only the surface, but also the bulk must be hydrogen free, too. Ion pump element is ’vacuum fired’ 2 hours @ 750°C, at 1E-5 mbar, then, the complete pump is processed under vacuum at 450°C. PB - JACoW Publishing CP - Geneva, Switzerland ER -