Abstract: A linear electron beam evaporation source for a high vapor temperature material such as uranium, the source being provided with a filamentary emitter and apparatus for controlling the filament electron emission to maintain an approximately constant current per filament unit length. A control structure is provided and operated to create a space charge in the vicinity of the electron emitting filament such that the current density of the electron beam is controlled by the space charge rather than the local electron emissivity along the length of the filament.

Abstract: A probe for detecting the evaporation rate of an electron beam evaporation source and for monitoring induced ionization of the vapor. A negatively biased electrode responds to ions in the vapor to measure the ion current density. The ions measured may result from the process of vaporization or from laser produced isotopically selective ionization. The probe provides a current output which is detected as an indication of vaporization or laser ionization rate.

Abstract: An electron beam vapor source for use in laser enrichment of uranium and providing fast response intermittent vaporization to permit interruption of the enrichment process without wasting vapor or requiring long term reheating.