| 摘要 |
Ion source with ionisation by electron bombardment, in which the combined action of a uniform magnetic induction B, and a radial electrostatic field E, perpendicular to B, makes it possible, based on electron emission from a short filament of length I, to establish an ionising space charge over the whole outline of the source. The ions accelerated by E towards the centre of the source are then focused by a suitable optic on the axis of the system which exhibits axisymmetry. If the radius of the source is R, the ion current extracted is 2 pi R/l times larger than the current extracted from a conventional source using the same filament. <IMAGE>
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