Feasibility of constructing an electron photoinjector based on synchrotron or undulator radiation

An analysis is made of the feasibility of using synchrotron or undulator radiation to illuminate the cathode of an electron photoinjector. It follows from simple estimates that there are parameters of an accelerator, undulators, and path-bending magnets which can ensure intense electron emission as a result of irradiation of the photocathode surface by intense short pulses of short-wavelength radiation.