Radio-frequency compressed electron pulse-width characterization by cross-correlation between electron bunches and laser-induced plasma

A method is proposed to determine the temporal width of high-brightness radio-frequency compressed electron pulses based on cross-correlation technique involving electron bunches and laser-induced plasma. The temporal evolution of 2-dimensional transverse profile of ultrafast electron bunches repelled by the formed transient electric field of laser-induced plasma on a silver needle is investigated, and the pulse-width can be obtained by analyzing these time-dependent images. This approach can characterize radio-frequency compressed ultrafast electron bunches with picosecond or sub-picosecond timescale and up to 10⁵ electron numbers.