Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
One of the major problems affecting the efficiency of high power microwave devices is that of secodary electron emission. It is a well-known fact that efficiency can be greatly improved by using depressed collectors comprised of low yield materials. This experimental research benchmarks existing material yield curves and classifies yields of new material for use in depressed collectors. Secondary Electron Yield is defined as \delta=I_s/I_p where I_s is the secondary electron current and I_p is the primary electron current. Since I_p = I_s+I_target yield can be obtained from delta=1-I_target/I_beam. Beam current is measured using a Faraday Cup connected to pico amp meter and target current is measured directly by pico amp meter. Beam spot size is kept minimal at 1-2mm. Results show that the secondary electron yield curve is dependent upon the incidence angle of the primary electrons.
* Work supported by a grant from AFOSR