  Results from large-scale theoretical cross section calculations for the total
photoionization of the 4f, 5s, 5p and 6s orbitals of the neutral tungsten atom
using the Dirac Coulomb R-matrix approximation (DARC: Dirac-Atomic R-matrix
codes) are presented. Comparisons are made with previous theoretical methods
and prior experimental measurements. In previous experiments a time-resolved
dual laser approach was employed for the photo-absorption of metal vapours and
photo-absorption measurements on tungsten in a solid, using synchrotron
radiation.
  The lowest ground state level of neutral tungsten is $\rm 5p^6 5d^4 6s^2 \;
{^5}D_{\it J}$, with $\it J$=0, and requires only a single dipole matrix for
photoionization. To make a meaningful comparison with existing experimental
measurements, we statistically average the large-scale theoretical PI cross
sections from the levels associated with the ground state $\rm 5p^6 5d^4 6s^2
\; {^5}D_{\it J}[{\it J}=0,1,2,3,4]$ levels and the $\rm 5d^56s \; ^7S_3$
excited metastable level. As the experiments have a self-evident metastable
component in their ground state measurement, averaging over the initial levels
allows for a more consistent and realistic comparison to be made.
  In the wider context, the absence of many detailed electron-impact excitation
(EIE) experiments for tungsten and its multi-charged ion stages allows current
photoionization measurements and theory to provide a road-map for future
electron-impact excitation, ionization and di-electronic cross section
calculations by identifying the dominant resonance structure and features
across an energy range of hundreds of eV.
