Decoding sequential vs non-sequential two-photon double ionization of helium using nuclear recoil

Abstract

Above 54.4 eV, two-photon double ionization of helium is dominated by a sequential absorption process, producing characteristic behavior in the single and triple differential cross sections. We show that the signature of this process is visible in the nuclear recoil cross section, integrated over all energy sharings of the ejected electrons, even below the threshold for the sequential process. Since nuclear recoil momentum imaging does not require coincident photoelectron measurement, the predicted images present a viable target for future experiments with new short-pulse VUV and soft X-ray sources.

4 pages, 3 figures

References in corpus (1)

• Signatures of direct double ionization under XUV radiation

Cited by in corpus (6)

• Universal features in sequential and nonsequential two-photon double ionization of helium
• A numerical study of two-photon ionization of helium using the Pyprop framework
• Two-photon double ionization with finite pulses: Application of the virtual sequential model to helium
• Role of intermediate continuum states in exterior complex scaling calculations of two-photon ionization cross section
• Calculation of multiphoton ionization amplitudes and cross sections of few-electron atoms
• Control of concerted back-to-back double ionization dynamics in helium