| 摘要 |
PURPOSE:To operate an electron gun device under maximum efficiency to improve productivity, by putting a magnetization coil around a permanent magnet. CONSTITUTION:Electrons radiated from a heated filament 1 are deflected so as to pass on an electron beam orbit 2. Raw-material matter 6 housed in a crucible 5 is irradiated with these deflected electrons, heated, dissolved, and vaporised. In case that strength of a magnetic field made by the permanent magnet 3 becomes weakened, the electrons radiated from the filament 1 pass through an electron beam orbit 8, for example, not irradiating the raw-material matter 6. In this case, definite current for magnetization is supplied to the magnetization coil 7, magnetizing the permanent magnet 3 in desirable strength. Hence, the electrons (thermions) radiated from the filament 1 pass through an optimum electron beam orbit 2 to irradiate the raw material-matter 6 in the crucible 5 in maximum efficiency.
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