A High Intensity Mass-Spectrometer

Abstract

A mass-spectrometer has been constructed in which is used a new type of magnetic lens capable of focussing on a slit all the positive ions of a given mass from an extended source. Electrostatic focussing permits 12 percent or more of the ions from an area of 30 sq. cm to be brought into a nearly plane beam and focussed by the lens. Practically complete separation of the potassium isotopes has been accomplished with an ion current of 0.1 milliampere for ${\mathrm{K}}^{39}$, which deposits one milligram in seven hours. Samples of ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$ have been collected.