AVS 52nd International Symposium
    Vacuum Technology Tuesday Sessions
       Session VT-TuP

Paper VT-TuP12
Electron Stimulated Desorption of Hydrogen Physisorbed on a Cold Cupper Surface

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Vacuum Technology Poster Session
Presenter: S.-S. Hong, Korea Research Institute of Standards and Science
Authors: S.-S. Hong, Korea Research Institute of Standards and Science
M. Shoaib, Pakistan Vacuum Society
Y.-H. Shin, Korea Research Institute of Standards and Science
K.-H. Chung, Korea Research Institute of Standards and Science
I. Arakawa, Gakushuin University, Japan
Correspondent: Click to Email
Study of hydrogen is indispensable in vacuum technology for extreme high vacuum (XHV). XHV can only be achieved by minimizing the hydrogen outgassing from the materials used in vacuum system. Outgassing phenomena can be classified into four categories by the combination between the source (chemisorbed or physisorbed species) and the process (thermal or electronic desorption). We have been investigating the electron stimulated desorption at the cold surface on which hydrogen is physisorbed in order to clarify the fundamental process of outgassing from a cryopump which is exposed to charged particles or radiation. An experimental system was constructed in the Korea Research Institute of Standards and Science (KRISS). The system consists of a UHV chamber, two turbomolecular pumps and a dry pump, a residual gas analyzer, an electron gun and a micro channel plate for ion detection. The time of flight spectrum of the desorbed ions is obtained using a multi channel scaler. ESD yields of the H+ ion were systematically measured as a function of H2 pressure upon the cold surface and the amount of adsorption of H2.