Method of treating a workpiece with electron beams and apparatus therefor

摘要

A vacuum chamber for welding in which to place a workpiece is hermetically connected to a vacuum chamber for an electron beam gun in which to place an electron beam gun, and the former is kept at a vacuum of 1x10-4 Torr while the latter, at a vacuum of 1x10-6 Torr. The distance between the electron beam gun and the surface of the workpiece is made greater than the mean free path of gas molecules and metal vapor molecules generated in treating, e.g., 1.85 m. Two focusing coils are arranged to prevent the expansion of the electron beams.