Abstract: An electron beam system comprises a vacuum enclosure, a source of electrons within the enclosure, and a passive pump located within or in communication with the enclosure for pumping gases from the enclosure. A supplemental active pump is coupled to the vacuum enclosure and functions simultaneously with the passive pump for pumping from the enclosure gases not removed, or not removed efficiently, therefrom by the passive pump.

Abstract: A high performance, vacuum compatible electromagnetic electron lens coil for electron beam systems has reduced gaseous emissions and improved heat dissipation capability. It comprises a wound coil of electrically conductive wire sheathed in a selected thermoplastic resin insulator. The wire insulator is coated with a hermetic layer of low vapor pressure metal. The low vapor pressure and hermetic sealing properties of the layer provide ultra high vacuum compatibility of the coil. The high thermal conduction property of the layer provides high heat dissipation capability and therefore permits high current densities in the coil.