Segmented SRF Cryomodules

Linear accelerators based on Superconducting Radio Frequency (SRF) cavities have become increasingly important and wide spread. This chapter reviews the design and operation of four different SRF segmented cryomodules. These cryomodules were used in projects from the 1980s to the 2010s and as such this chapter provides a good overview of the development of this type of cryostat. Topics described include: requirements, cooling of SRF cavities, tuners, power couplers, structural and thermal insulation systems, magnetic shields, vacuum systems and instrumentation. Performance results from both prototypes and series operation are presented.