TIME-DEPENDENT AND TIME-INDEPENDENT METHODS APPLIED TO
MULTIPHOTON IONIZATION OF HELIUM

L.R. Moore, D.H. Glass, J.S. Parker, E.S. Smyth, P.G. Burke and K.T. Taylor

A comparison is made between results from the R-matrix-Floquet (RMF) approach
and the direct numerical integration of the full-dimensional time-dependent
Schr\"odinger equation (TDSE) for the multiphoton ionization of helium. Good
agreement has been obtained in the intensity range $2\times 10^{13}$ Wcm$^{-2}$
to $4\times 10^{14}$ Wcm$^{-2}$ at laser wavelengths of $248$ nm and shorter
where only single electron ejection takes place.