Time-dependent<b><i>R</i></b>-matrix theory of multiphoton processes

Abstract

A new time-dependent R-matrix theory of multiphoton processes is described which can be applied to an arbitrary many-electron atom. The theory is complementary to the R-matrix Floquet theory developed by Burke, Francken and Joachain (1991 J. Phys. B: At. Mol. Opt. Phys. 24 761) enabling processes involving higher laser field intensities and shorter laser pulses to be treated. The new theory is illustrated by analysing the multiphoton ionization of a charged particle bound initially in a one-dimensional potential well where the results are compared with an independent R-matrix Floquet calculation.