Near-threshold triple-photoionization cross section of lithium

Abstract

The triple-photoionization cross section of atomic Li was measured near its threshold. Our results can be described by a threshold power law up to Ϸ5 eV with an exponent of 2.05͑25͒ which is consistent with a previous experiment and theoretical predictions. At higher energies, we find that the cross section is well described by the threshold law for double ionization. The present analysis is based on the notion that for sufficient excess energy, triple photoionization of Li is reasonably well described by a double ionization of the inner electrons followed by a shakeoff of the outer electron.

Triple photoionization of lithium near threshold

“…For the present case of Lithium triple ionization (I = 7.478 a.u.) the experimental results reach only down to 2 eV above threshold [2]. The corresponding fit of the experimental data with Eq.…”

“…Sq, 32.80.Fb, 34.80.Dp Triple photoionization of Lithium is the most fundamental atomic process involving three bound electrons. Only recently Wehlitz et al succeeded in measuring the triple photoionization cross section down to 2 eV above threshold [1,2]. Subsequent experiments have produced various double ionization cross sections, also very close to threshold.…”

The Coulomb four-body problem in a classical framework: triple photoionization of lithium

“…where R 3+ and R 2+ are the experimental triple-to-single and double-to-single photoionization ratios, respectively [3,4,13]. Figure 1b also illustrates the numerical effort involved in computing P 3+ .…”

“…Experimentally, the first data on triple ionization appeared only recently [3,4], compared to data on photo double ionization which date back to the late sixties of the last century [5].…”

VUV/EUV ionising radiation and atoms and ions: dual laser plasma investigations

“…The measured cross section never exceeded the extremely low value of six barns ( Figure 6). Later experiments investigated the near threshold behaviour of the cross section and provided an analysis in terms of a power law (Wehlitz et al 2000). Analogous experiments to those carried out on helium, in which the directions and momenta of the electrons and ion are all measured simultaneously (Rau 1992), remain a challenge for the future.…”