Absolute photoionization cross section from the 6s6p 1,3P1 excited states of barium

We present photoionization cross section measurements from the 6s6p P-1(1) and P-3(1) excited states of barium at and above the first ionization threshold. The experiments have been performed using a thermionic diode ion detector in a space charge limited mode in conjunction with a Nd: YAG laser system and the saturation technique to determine the photoionization cross sections. The absolute values of the photoionization cross section from the 6s6p P-1(1) and P-3(1) excited states at the first ionization threshold have been determined as 90 +/- 14 Mb and 102 +/- 15 Mb, respectively. The measured values of the photoionization cross section from the 6s6p P-1(1) excited state are compared with available experimental and theoretical work, while the absolute photoionization cross sections from the 6s6p P-3(1) excited state are reported for the first time.