GENERATION AND MEASUREMENT OF 50-FS (RMS) ELECTRON PULSES

An electron source has been developed at the Stanford SUNSHINE facility which can produce electron bunches as short as 50 fs (rms) with (2-4.6) X 10(8)e- per microbunch. This source consists of a 2.6 MeV rf gun with a thermionic cathode and an alpha magnet for bunch compression. Coherent transition radiation emitted at wavelengths equal to the bunch length and longer is used in a Michelson interferometer to determine the bunch length by optical autocorrelation. The experimental setup and results of bunch length measurements are described.