High-Intensity Ion Source

An ion source that does not require a filament has been developed for use in the cyclotron. Positive ions, from an oscillatory region within a hollow anode, bombard the cathodes at the ends and maintain them at emission temperatures. The source aperture is a lateral slit, $\frac{3}{32}\text{×2}\frac{1}{4}\mathrm{in}$ ., in the wall of the anode. With a 10 kv (dc) accelerating potential, stable hydrogen ion beams of 330 ma (82 percent protons) have been obtained. Ion output increases as hydrogen gas feed is increased from 1 to 12 cc/min (N.T.P.). The average proton production efficiency has been 20 percent.