Discrimination of K⁺ Thermal Ions Emitted from Bare and Partly Coated Surfaces of a Polycrystalline Tungsten Ribbon with Potassium Nitrate

Abstract

The K⁺ thermal ions emitted in the same time from bare and partly coated surfaces of a polycrystalline tungsten ribbon with potassium nitrate have been discriminated by the measurement of energy distribution curves of the ions. The distribution curves have been obtained by the technique of electrical differentiation of the retarding voltage curves in a method similar to Auger electron spectroscopy with a four-grid low energy electron diffraction optics. The assignment of emission surfaces for K⁺ thermal ions emitted in the same time has been made clear by a comparison with retarding voltages at maximum of the energy distribution curves for K⁺ thermal ions emitted from two different polycrystalline tungsten ribbons with bare and wholly coated surfaces with potassium nitrate.