2025/06/30 by Seidel, Andreas, Zepter, Carola, Sävert, Alexander +2
#Accelerator Physics (physics.acc-ph) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2506.24107
Determining the pulse duration of femtosecond electron bunches is challenging and often experimentally invasive. An effective method for measuring the duration based on the time-dependent variations in electron beam divergence induced by a passive plasma lens is described. Reconstruction of the temporal shape of the electron bunch down to c ⋅ dt=10 nm (∼ 30 as) without external RF-cavities or multi-octave spanning spectrometer is shown numerically. Experimental data from a ∼ 3fs electron bunch demonstrates practical applicability of this method. While this approach can be used with any high current electron beam, it is particularly well matched to laser-driven and particle-driven wakefield accelerators and also accommodates electron beams with a time-dependent beam-energy (eg. 'chirp').