USE OF MECHANICAL DEFLECTION TO ELIMINATE METALLIC VAPOR-DEPOSITION ON VACUUM VIEW PORTS

Metallic vapor emitted from a source can be deflected prior to deposit ing on an observation view port by imposing fans whose blades rotate p erpendicular to the atoms flight path. The effectiveness of this techn ique is demonstrated with tin vapor in terms of relative rate depositi on and visual examination as a function of the imposed rotation rate. The consequence of fan rotation on sample visibility is shown to be ne gligible.