Proposed method for measuring the duration of electron pulses by attosecond streaking

We propose a method to measure the duration of ultrashort electron pulses. The electron pulse to be measured impinges on a solid target, causing the emission of Auger electrons through impact ionization. The energy spectrum of the Auger electrons is altered in the presence of an intense femtosecond laser field. Due to the extremely short lifetime of the Auger effect, this effect can be used to generate cross correlation between a laser and an electron pulse. The method is applicable to electron pulses ranging from hundreds of attoseconds to hundreds of femtoseconds in duration, and for a few hundreds of electron volts to relativistic energies.

Figure 1

Basic arrangement of electron pulse duration measurement. $\mathrm{P}$ indicates the direction of polarization of the laser pulse.

Figure 2

(Color online) Electron spectra for a long-pulse case at delay time $\mathrm{\Delta }t=0$, i.e., when electron and laser pulse maxima coincide. The dashed blue curve (QM) shows the result of a quantum mechanical calculation following Eq. (5), while the red solid curve (Class) shows the spectrum calculated (classically) using Eq. (1). The inset shows the original line without laser. The total number of electrons is the same for all curves.

Figure 3

(Color online) Calculated electron spectra. (a) Spectrum for long-pulse conditions. Electron pulse duration $100\mathrm{fs}$; laser pulse duration $50\mathrm{fs}$. Auger line applied oxygen KLL at $500\mathrm{eV}$. (b) Spectrum for short-pulse conditions as a function of time delay. Electron pulse duration $500\mathrm{as}$; laser pulse duration $5\mathrm{fs}$. Auger line Ti KLL at $4.06\mathrm{keV}$. Time zero is defined as the temporal delay at which both pulse maxima coincide. The color scale is normalized to the intensity of the original Auger line.