Positron scattering on helium, neon and argon above 4 eV

Convergent close-coupling method for positron scattering from noble gases

“…As we go from the lighter Ne atom to the heavier Ar, Kr and Xe atoms the scattering length grows in absolute value significantly. This is consistent with a large increase in the static dipole polarizability, see [10][11][12][13][14][48][49][50][51][52][53][54][55][56][57]. The present theory is labeled as CCC, and the other theory is from [22,23].…”

Recommended Positron Scattering Cross Sections for Atomic Systems

“…There have been many studies of positron scattering from neon (Ne), with measurements of the total cross section [65,161,162,165,[169][170][171][172][173][200][201][202][203][204][205], the positronium formation cross section [65,182,185,[206][207][208][209], and the direct ionization cross section [26,189,191,192,208,[210][211][212][213] having been reported. We also note several measurements [207,208,214] of the total ionisation cross section (direct ionization + positronium formation), and a measurement of the direct double ionization cross section [215].…”

“…Positron scattering from argon (Ar) has possibly received more experimental and theoretical attention than any of the other heavy rare gas atoms, no doubt due to the ready availability and use of argon as a target gas. There have been a large number of total scattering cross section measurements [65,161,162,165,[171][172][173][200][201][202]204,[251][252][253][254], as well as measurements of the positronium formation cross section [65,181,182,185,[207][208][209]236,[255][256][257][258], electronic excitation [8] and the direct ionization cross section [189,[191][192][193]210,211,213]. There have also been a considerable number of theoretical calculations of these various processes [65,97,100,126,128,129,197,216,218,…”

Positron scattering from argon: total cross sections and the scattering length

“…A very thorough review of the available experimental and theoretical investigations into positron scattering from argon was recently provided by Jones et al [1], and so we do not repeat all of those details again here. Rather, we note that there is a sizeable body of previous work, both experimental [1][2][3][4][5][6][7] and theoretical [1,[8][9][10][11][12][13][14], that remains, in general, in only marginal to fair agreement with one another [1]. This is a serious problem, as the noble gases represent systems, for a variety of experimental and theoretical reasons [1], for which you might hope to be able to provide detailed 'benchmark' cross sections [15].…”