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

Abstract

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 Schrödinger equation is solved using a coupled channel method. We show that for ultrashort pulses the angular distribution of ejected electrons depends on the pulse duration and provides novel insights into the role of electron correlations in the two-electron photoemission process. The angular distribution at energies near the ``independent electron'' peaks is close to dipolar while it acquires in the ``valley'' of correlated emission a significant quadrupolar component within a few hundred attoseconds.

17 pages, 6 figs

References in corpus (3)

• Attosecond double-slit experiment
• Electric-octupole and pure-electric-quadrupole effects in soft-x-ray photoemission
• Signatures of direct double ionization under XUV radiation

Cited by in corpus (7)

• Probing Electron Correlation via Attosecond XUV Pulses in the Two-Photon Double Ionization of Helium
• Universal features in sequential and nonsequential two-photon double ionization of helium
• Electron correlation in two-photon double ionization of helium from attosecond to FEL pulses
• Probing time-ordering in two-photon double ionization of helium on the attosecond time scale
• Multiphoton ionization and stabilization of helium in superintense xuv fields
• Photoionisation of Rubidium in strong laser fields
• Correlations between the final momenta of electrons and their initial phase-space distribution in the process of tunnel ionization