| 摘要 |
In an electron beam heating and/or evaporator, an electron gun projects a beam of electrons over an arcuate beam path to a crucible containing a target material for heating and/or evaporating the target material in use. The electron beam passes between a pair of generally parallel magnetically permeable pole pieces of a beam focus magnet energized by a primary source of magnetomotive force to produce a main field transverse to the direction of the arcuate electron beam. This main field causes the electron beam to take the arcuate trajectory. An auxiliary electromagnet structure is magnetically coupled between the pole pieces in a region adjacent the electron beam. This auxiliary electromagnet structure includes a first set of windings for skewing the main magnetic field to produce lateral deflection of the beam spot over the target area and a second electromagnetic coil energizable to increase or decrease the intensity of the main field to provide a longitudinal sweep of the beam spot on the target.
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