Beam Asymmetry, Divergence and Energy Spread Effects on the Radiation from Planar Undulators

The theoretical study of the effect electron beam parameters, in particular, emittance and its asymmetry on radiation from relativistic electrons undulators is conducted both analytically numerically. reasons for odd even harmonic generation are explored. difference underlying physical spontaneous stimulated harmonics free lasers (FELs) elucidated. generalized forms special functions Bessel Airy type employed to account off-axis angular effects together with energy spread. A comparative analysis spectra different beams performed. examples at SPARC LEUTL given. properties analyzed. alternative approaches other authors also analytical calculation powers FELs. results compared existing experimental data.