Angular distribution in two-photon double ionization of helium by intense attosecond soft X-ray pulses

I. F. Barna, J. Wang, J. Burgdoerfer

We investigate two-photon double ionization of helium by intense ($10^{15}W/c{m}^2$) ultrashort ($\approx 300$ as) soft X-ray pulses (E = 91.6 eV). The time-dependent two-electron S…