In the
first part of the talk some general statements are made regarding applications
suitable for utilizing energy recovered linacs (ERLs) by contrasting
their potential performance to that of single pass linacs and storage
rings. As a result of their potential for extremely good beam quality
in combination with very high average beam current, ERLs have been used
and considered as drivers of both FEL and partially coherent photon
sources, from THz through x-rays; as a suitable technology for high
energy electron cooling; and as continuous or semi-continuous electron
beam source for high energy colliders. At present, beam requirements
tend to be highly matched to end use requirements. By reviewing some
of the many examples which have either been reduced to practice, or
are being explored presently, one can develop an appreciation for the
wide range of parameters being considered in ERL applications.
*Work supported by the United States Department of Energy under Contract
DE-AC05-84-ER40150