AVS 49th International Symposium
    Applied Surface Science Thursday Sessions
       Session AS-ThM

Paper AS-ThM7
Study on Electron Emission from Some Metals and Carbon Materials and the Surface Characterization

Thursday, November 7, 2002, 10:20 am, Room C-106

Session: Practical Surface Science I
Presenter: S. Kato, KEK & The Graduate University for Advanced Studies, Japan
Authors: S. Kato, KEK & The Graduate University for Advanced Studies, Japan
M. Nishiwaki, The Graduate University for Advanced Studies, Japan
Correspondent: Click to Email
We focus on secondary electron emission from metals and carbon materials in conjunction with potential and actual problems of photoelectron instability and electron multipactering in several particle accelerators in the world. Therefore it is quite important to explore promising materials which have secondary electron yields as low as possible. While a plenty of reports on investigation of secondary electron emission was made over years, the experimental conditions with poor vacuum have deteriorated the quality of the data and lack of surface characterization has made understanding the data and applying the data to surface engineering confusedly difficult. For this purpose, an UHV system was newly developed which consisted of a x-ray source, an ultraviolet photon source, an electron gun, an ion gun, residual gas analyzers, a hemispherical energy analyzer and a sample manipulator with cooling and heating capabilities. This system gives us useful basic informations about dependences of secondary electron yields and the energy distributions on primary electron energy, material, the material temperature and the surface state. In-situ surface characterization of the materials was also performed before and after conditionings such as heating, gas exposure and electron or ion bombardments. Prepared materials were oxygen free copper (single and poly-crystalline), pure titanium, stainless steel, isotropic graphite and carbon fiber reinforced carbon composite. Mechanical surface roughing on the materials was attempted to reduce electron emission in addition. The introduction of the system, the measured results and the discussion will be described in this paper.