Frequency Resolved Optical Gating for Time-Resolving Intra-Atomic   Knock-Out in Double Ionization with Attosecond Pulses
  We develop the two-electron attosecond streak camera under realistic conditions using a quasi-classical model. We assume extreme ultra-violet (XUV) attosecond pulses with a full width at half maximum (FWHM) of 24 attoseconds, centered at 120 eV and a streaking infrared laser field of 1600 nm, and intensity of $1.8 \times 10^{12}$ W/cm$^2$. The proposed method is shown to be capable to time resolve intra-atomic collisions in double ionization. 
H. Price, A. Staudte, P. B. Corkum, and A. Emmanouilidou
physics.atom-ph