Assignment of emitting surfaces for thermal ions by their energy distributions

The K+ thermal ions emitted simultaneously from bare surface and partly coated one of a polycrystalline tungsten ribbon with potassium nitrate have been discriminated by the measurement of the ion energy distribution curves. These curves have been obtained by electronic differentiation of retarding voltage curves in a method similar to widely used LEED-Auger system. The assignment of emitting surfaces for the K+ thermal ions has been made by a comparison with retarding voltages at maxima of the energy distribution curves for K+ thermal ions emitted from two separate polycrystalline tungsten ribbons with a wholly bare surface and a wholly coated one with potassium nitrate. (author)