Subpicosecond electron single-beam diagnostics by a coherent transition radiation interferometer and a streak camera

Longitudinal bunch distributions of subpicosecond and picosecond electron beams have been evaluated by the coherent transition radiation (CTR) Michelson interferometer with the reconstruction procedure obtained from the interferograms. The results were compared with those obtained from the femtosecond streak camera whose time resolution is 200 fs at the full-width at half-maximum (FWHM). From the comparison, the reliability of the interferometry to evaluate the subpicosecond electron pulse, which is close to the time resolution of the femtosecond streak camera, has been discussed in detail. Further, the validity of the application of the Kramers–Kronig relations and the extrapolation of missing data in the measurements is also discussed.