Ion Sources for Mass Spectroscopy

Three spectroscopic methods of exciting spectra have been examined as possible sources of positive rays. The vacuum vibrator, a mechanically interrupted low potential spark, has been found to give positive ions although the source is not constant. The discharge of a large condenser charged to 60 kilovolts between metal electrodes, has been found unsatisfactory as a source of positive ions. A high frequency alternating spark coupled inductively to a primary oscillating spark circuit, is a strong convenient source. The ions may be accelerated to form a beam, and, with the Thomson parabola method of analysis, it has been found that multiply charged ions of the electrode elements are formed in all cases tried.