PROGRESS IN THE DESIGN OF A DC FEL POWER SOURCE USING A PELLETRON DRIVER

are required. It is also likely that FEL operation will result in a large spread of electron energies. These design constraints require the development of a highly efficient electron beam collector as well as beam optics capable of recirculating beams with a large energy spread. We present collector and beamline designs and include electron optics studies for the full range of operating conditions.