Electron Collisions with Argon at Low and Intermediate Energies

We have further developed the $B$-Spline $R$-matrix (BSR) method~[1] and the corresponding computer code~[2] to allow for a large number of pseudo-states in the close-coupling expansion. In the present work, we carried out semi-relativistic (Breit-Pauli) close-coupling calculations for elastic scattering, excitation, and ionization of argon from both the ground state and the metastable excited states. Coupling to the ionization continuum through the pseudo-states is important for low-energy elastic scattering (to represent polarizability effects), for excitation in the ``intermediate'' energy regime of about 1-3 times the ionization potential, and to allow for the calculation of ionization processes by transforming the results obtained for excitation of the positive-energy pseudo-states. The current results represent a significant extension of our earlier near-threshold work~[3] on the e-Ar collision system. Many of these data are now available in the LXCat database~[4].\\[4pt] [1]~O.~Zatsarinny and K.~Bartschat, J. Phys. B~{\bf 46} (2013) 112001.\\[0pt] [2]~O.~Zatsarinny, Comp. Phys. Commun.~{\bf 174} (2006) 273.\\[0pt] [3]~O.~Zatsarinny and K.~Bartschat, J.~Phys.~B~{\bf 37} (2004) 4693.\\[0pt] [4]~http://www.lxcat.laplace.univ-tlse.fr/database.php