摘要 |
A method for irradiating a workpiece, such as a strand, by charged particle, e.g. electron, bombardment is in accordance with the following steps: generating a charged particle beam at one end of an elongated vacuum chamber by thermionic emission from an elongated emitter, accelerating the ribbon beam toward a longitudinally extending, radially curved window member, such as a tube, extending tranversely across another end of the vacuum chamber, the window tube having a length related to the width of the ribbon beams, dynamically deflecting the ribbon beam periodically back and forth to define a sweep field which contains the curved window member therein in accordance with a common predetermined deflection driving signal, dynamically converging the deflected ribbon beam onto the active area of the curved window in consonance with the deflection of the beam, in accordance with a predetermined convergence driving signal phase related to the deflection driving signal, so that the ribbon beam sweeps continuously and substantially perpendicularly over substantially the entire active area of the window, and drawing the workpiece to be irradiated through a passageway defined adjacent to the active area of the window tube as the ribbon beams sweep over the active area, thereby to cause charged particle bombardment of the workpiece. A particle beam irradiator, preferably implemented as a coaxial electron ribbon beam and its irradiation method form aspects of the present invention.
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