Coplanar symmetric (e, 2e) cross sections for argon 3s ionization

Abstract

The triple differential cross section for electron impact ionization of the 3s orbital in argon (binding energy 29.3 eV) has been measured in the coplanar symmetric geometry. The measurements have been performed at incident energies of 129.3, 69.3, 49.3 and 37.3 eV. This corresponds to detecting two equal outgoing electrons with energies of 50, 20, 10 and 4 eV. Comparisons with previous measurements for ionization of the 3p orbital of argon under the same kinematic conditions show significant orbital-dependent effects.

Triple differential cross section in (e, 2e) collisions for sodium in a coplanar symmetric geometry

“…Besides the variation trends for the forward and backward scattering peaks, at incident energies of 35 These similar bumps were also observed in the TDCS for s valence orbitals of Mg [15], K [15], Ca [15], Ne [35], Ar [36], and Kr [37], but not observed in He [38,39]. Considering the similarities and differences in electronic structures of these atoms, we calculated the TDCS of Na by switching off the interaction between active electron and passive s or p electrons from the distorting potentials.…”

Exchange effects in low energy electron impact ionization of the inner and outer shells of argon

“…In figure 5, coplanar symmetric results for ionization of the 3s shell are compared with the experimental data of Haynes and Lohmann (2001a). For the coplanar symmetric geometry, both final state electrons are observed at the same angle on opposite sides of the beam direction and the electrons have the same energy.…”

“…Surprisingly, it has been only very recently that the first experimental TDCS results for low-energy electron impact ionization of a heavy target in the coplanar asymmetric geometry have been reported for ionization of the 3s and 3p shells of argon (Haynes and Lohmann 2000, 2001a, 2001b. In those works, very poor agreement was found with the DWBA calculations of Madison and Lang (1981) and McCarthy (1995).…”

Comparison of theoretical and absolute experimental fully differential cross sections for ion-atom impact ionization

“…The important remaining questions are mainly concerned with nearthreshold ionization of hydrogen and this problem has recently attracted intense interest and controversy (Bencze and Chandler 1999, Bray 1999, Stelbovics 1999, Rescigno et al 1999, Bray 2000, Bray et al 2001, Baertschy 2002). The situation is much different for electron-impact ionization of the heavier inert gases where experiment and theory are not in good accord for incident electron energies below about 100 eV (Haynes and Lohmann 2001aand 2001b, Biava et al 2002. It should be noted that the different theoretical methods discussed in the above cited papers all give essentially identical total ionization cross sections.…”