Photoionization cross sections of iron isonuclear sequence ions: Fe^{2+} to Fe^{6+}

We have measured the absolute photoionization cross sections of Fe2+ to Fe6+ ions in the photon energy range covering the first ionization threshold up to 160 eV. Particular interest is emphasized on the region of the 3p -> 3d excitations. The experimental data are compared to the results of calculations we have performed using a spectral opacity code, as well as to available R-matrix and one-electron calculations. It is shown that often the theoretical results tend to overestimate the intensity of the 3p -> 3d photoexcitations. An anomalously low value of the integrated oscillator strength is measured for Fe2+ ion.