Abstract: A system for sealing the working vacuum chamber of a charged particle beam machine which is movable with respect to a workpiece is disclosed. The system includes a housing with a central compartment having wire-shaped elements urged against the workpiece to provide a seal therebetween, and lateral compartments, each having a packing of sealing material which is biased against the workpiece surface of a spring arrangement. Rollers and a flexible lip seal arrangement having a flexible sheath of synthetic rubber are also disclosed.

Abstract: Disclosed is a method for producing an elongated weld seam in a workpiece by the use of a beam of charged particles, in particular an electron beam. According to the disclosed method, a beam of charged particles is directed to impinge on a workpiece and has a selected beam current, a selected accelerating voltage and is focused by a focusing field of a selected field strength. In order to produce a weld seam there is provided a relative motion between the charged particle beam and the workpiece, to move the point of impingement along the workpiece. The relative motion has a predetermined selected instantaneous velocity. The depth of penetration of the charged particle beam into the workpiece is varied by changing a parameter selected from the group consisting of the beam current and the velocity of relative motion.

Abstract: In a method of welding with a beam of charged particles, outside of a mobile vacuum chamber a gap between two workpiece parts is sealed by an elongated metal foil strip, two marginal zones of which being sealingly cemented to surface portions of said workpiece parts, said marginal portions being sufficiently spaced from the gap to avoid excessive heating of the adhesive during welding a seam along said gap. The preferred material for the foil strip is copper or austenitic steel.