GB797558A - Improvements in or relating to the separation of isotopes in electric and magnetic fields - Google Patents

Abstract

797,558. Mass spectrometers. SLEPIAN, J. Nov. 8, 1955 [Nov. 18, 1954], No. 31880/55. Class 39(1). Isotopes in an arc discharge between electrodes 35, 37, Fig. 1, are projected radially by a low intensity electric field set up by ring electrodes 45, 47 and are separated by a combination of circumferential D.C. electric fields produced by radial plates 71, 75 and an axial magnetic field produced by magnet N.S. The arc is isolated by radial or circumferential overlapping plates 67, 69 which float electrically relative to the arc. Overlapping segments 61, 63 and 61<SP>1</SP>, 63<SP>1</SP> may also be provided top and bottom of the apparatus. It is stated that space-charge neutralizing electrons are projected with the ions. Rings 45, 47 serve also to confine electrons axially. It is shown by analysis that in Fig. 5 ions tend to move outwardly in the spaces between radial plates 73 and 77 and between radial plates 71 and 75, and that heavier ions are drawn towards the negative plates and lighter ions towards the positive plates. In the spaces of negligible thickness between the plates 71 and 73 and between the plates 75 and 77 ions move inwardly. In modifications the radial plates may be subdivided into sections 73a. 73b, 73c, 73d at increasing potentials, Fig. 7, a pair of radial plates 201, 203 only may be used, Fig. 6, or sector plates 61, 63 and 61<SP>1</SP>, 63<SP>1</SP> may be used in place of radial plates, Fig. 8. Arc electrode 35, Fig. 1, is composed of material containing the isotopes to be separated, e.g., uranium or uranium oxide with a conductive addition. Electrode 37 is a cored carbon with the core composed of rare earth metal oxides. One electrode is movable. The vacuum is below 1/10 micron.