Some comments on emittance of H− ion beams

Abstract

Some properties of emittance, emittance distributions, and measurement techniques are reviewed. In comparing the results of measurements with several different types of H− sources with each other and with emittance formulae, it is concluded that the emittance of surface‐type sources is dominated by the effective ion temperature. Other effects, such as ion‐optical distortions, may account for the emittance of volume‐type sources.