ASPECTS OF ACCELERATOR-BASED PHOTOEMISSION

A high brightness electron beam with low energy spread is essential fo r a free electron laser intended to operate in the wavelength region b eyond the UV. Several hundreds of amperes peak current, an emittance o f several pi mm mrad or less and an energy spread of a few tenth of a percent are required. At present, photocathode linacs are the only dev ices that can produce such beams. The success of such a linac is stron gly dependent on the possibility to develop a high-efficient, stable p hotocathode and a high-power, stable drive laser used to illuminate th e cathodes. In this paper we present some result on our photocathode r esearch as well as our drive laser developments. (C) 1998 Elsevier Sci ence B.V.