  Recently, Bailey et al. performed iron opacity measurements on the Z machine
at Sandia National Laboratory in conditions close to the ones of the base of
the convective zone of the Sun. Such experiments have raised questions about
the physical models commonly used in opacity codes. To understand the
discrepancy between experiment and theory, More et al. investigated the role of
two-photon processes. In the present work we show, by a simple estimate and
using hydrogenic formulas, that due to the intensity of the backlight radiation
seen by the sample, such processes are likely to play an important role only
for highly excited states.
