Extraction electrode geometry for a calutron

Claim 1

In a calutron system including an ion source chamber provided with a side chamber cover having a narrow elongated ion exit slit, said chamber adapted to receive a vaporized charge material therein, means for producing an arc discharge which is associated with and passes through said chamber by means of arc defining slots for ionizing the charge material within said chamber, a magnetic field for effecting charge separation of the ions as they pass from said ion source exit slit, the improvement comprising an improved extraction electrode geometry including a negatively biased graphite accelerating electrode mounted adjacent to and parallel with said ion source chamber cover, said negative electrode being in the form of a first bottom-opened picture frame provided with a first plurality of spaced-apart metal rods mounted in parallel relation in the vertical legs of said frame, said frame being provided with a pair of flanges extending rearwardly from about the center of said frame''s vertical legs, a pair of spaced-apart metal rods mounted between and to said flanges, said pair of rods defining an ion exit slit in alignment with said ion source cover exit slit and in alignment with a slit formed between two of said first plurality of metal rods; and a graphite ground electrode mounted adjacent to and parallel with said negative electrode, said ground electrode being in the form of a second bottom-opened picture frame provided with a second plurality of spaced-apart metal rods mounted in parallel relation in the vertical legs of said second frame with two of said second plurality of rods defining an ion exit slit in alignment with all of said previously mentioned exit slits, whereby during operation of said calutron all of said metal rods except those used for providing said ion exit slits are utilized to establish equipotential surfaces over the rest of the front of said ion source for effecting a substantial reduction of un-ionized charge materials thereabout, thereby providing an increased ion output from said ion source and more stable calutron operation.