Ff. Baryshnikov et al., ON POSSIBLE USE OF AN ISOCHRONOUSLY SYNCHROTRON-RADIATION CONCENTRATOR IN THE PHOTOINJECTOR OF FREE-ELECTRON LASERS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 405(2-3), 1998, pp. 239-241
The possible use of intrinsic synchrotron radiation of a cyclic FEL fo
r the cathode illumination in the photoinjector - the electron source
for the basic FEL electron accelerator - is analyzed. It is shown that
it is necessary to collect the energy from the are which is much larg
er than the intrinsic SR divergence and to use isochronous optics. A s
imple algorithm is proposed to define the isochronously focusing surfa
ce which transforms the SR evolvent to a compact area.