Laser-plasma wakefield-based electron accelerators are expected to deliver ultrashort electron bunches with unprecedented peak currents. However, their actual pulse duration has never been directly measured in a single-shot experiment. We present measurements of the ultrashort duration of such electron bunches by means of THz time-domain interferometry. With data obtained using a 0.5 J, 45 fs, 800 nm laser and a ZnTe-based electro-optical setup, we demonstrate the duration of laser-accelerated, quasimonoenergetic electron bunches [best fit of 32 fs (FWHM) with a 90% upper confidence level of 38 fs] to be shorter than the drive laser pulse, but similar to the plasma period.
- wakefield accelerator
- plasma interactions
Debus, A., Bussman, M., Schramm, U., Sauerbrey, R., Murphy, C. D., Major, Z., ... Jaroszynski, D. A. (2010). Electron bunch length measurements from laser-accelerated electrons using single-shot THz time-domain interferometry. Physical Review Letters, 104(8), [084802 ]. https://doi.org/10.1103/PhysRevLett.104.084802