%0 Journal Article %T Low-beta structures %A M. Vretenar %J Physics %D 2012 %I arXiv %X 'Low-beta' radio-frequency accelerating structures are used in the sections of a linear accelerator where the velocity of the particle beam increases with energy. The requirement for space periodicity to match the increasing particle velocity led to the development of a large variety of structures, both normal and superconducting, which are described in this lecture. %U http://arxiv.org/abs/1201.2593v1