Cesium coverage on molybdenum due to cesium ion bombardment

Tompa, G. S.; Carr, W. E.; Seidl, M.
April 1986
Applied Physics Letters;4/21/1986, Vol. 48 Issue 16, p1048
Academic Journal
Cesium coverage due to Cs+ bombardment of a polycrystalline molybdenum surface was investigated in the incident energy range below 500 eV. When the surface is exposed to a Cs+ beam the work function decreases until steady state is reached with a total dose of less than ≊1×1016 ions/cm2. The steady state work function reaches a minimum at an incident energy of ≊100 eV and slowly increases with bombarding energy. Cesium coverage of a target is proportional to the ratio (1-β)/γ, where β is the reflection coefficient and γ is the sputter yield. This ratio is large for molybdenum because of its low mass and high binding energy. Implications of these results for H- surface conversion sources are discussed.


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