The success of high brightness photoinjectors as drivers of SASE FEL experiments
has raised again the interest in the beam dynamics associated with intense,
quasi-laminar, space charge dominated electron beams: the relevant phenomena
observed in such a regime of beam physics are presented and discussed in this talk.
Most of the emphasis is focused on the analysis of the so called emittance
correction technique, which is applied in the operation of RF guns in order to
enhance the performances of these devices in terms of the attainable beam brightness, i. e.
minimising the beam emittance in high peak current beams. A theoretical introduction
of this process is presented, based on an envelope equation approach, which leads
to the concept of invariant envelope. The implications of such a concept are
discussed and specific examples related to the SPARC project (INFN) are given
to compare the analytical predictions to the results of numerical simulations
made with code HOMDYN. A particular enphasis will be addressed to a possible
Superconducting RF Gun design based on the new working point for a split photoinjector.
Talk Slides: PDF