Measuring and Analyzing Transverse Low-Energy Ion Beam Emittances

The transverse emittance of an ion beam describes its transverse size as the particles are transported from a source to a target. It allows for predicting beam losses in limiting apertures and the beam focus size at the target. Various definitions and issues are discussed. The most common and emerging measuring techniques are presented, including their advantages. Several methods of emittance data analysis, their accuracy and trustworthiness, are discussed.