R-matrix approaches for electron and photon-driven processes in atomic physics

Last updated October 7, 2020 by Alessandro Ferraro

Wednesday, September 23rd 2020, 04:00 PM, Microsoft Teams meeting

Speaker: Kathryn Hamilton (Drake University)

R-matrix methods have achieved much success in the areas of time-dependent and time-independent computational atomic physics [1]. Originally developed to describe nuclear resonances, R-matrix theory has been extensively applied to the treatment of atomic and molecular physics problems since the late 1960s. Two of the more recently developed R-matrix approaches, and the focus of this seminar, are the time-independent B-spline atomic R-matrix (BSR) [2] and the R-matrix with time-dependence (RMT) [3] methods.

BSR and RMT both offer a fully multielectron treatment of their atomic target; however, quite often the systems they are applied to can be adequately described by accounting for the dynamics of only a single active electron (SAE). In this seminar, I will first discuss their computational implementation, including making the codes and examples publicly available through the recently developed Atomic and Molecular Physics Gateway [4]. Furthermore, I will present a comparison of results from these sophisticated R-matrix methods and related SAE approaches when applied to a variety of atomic physics processes. Specifically, I will concentrate on a recent BSR study of electron collisions with neutral indium [5] before discussing the application of RMT to describe the interaction of short laser pulses in both the strong-field and perturbative regimes with argon atoms.

[1] P. G. Burke, “R-matrix theory of atomic collisions: Application to atomic, molecular and optical processes”, Springer (2011)

[2] O. Zatsarinny and K. Bartschat, J. Phys. B 46 112001 (2013)

[3] A. C. Brown et al., Comput. Phys. Comm. 250 107062 (2020)

[4] https://ampgateway.org

[5] K. R. Hamilton et al., Phys. Rev. A 102 022801 (2020)

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