Abstract
We report on an improved measurement of absolute cross sections for photoionization from an excited Ba i state. In a barium oven irons are produced using a two-step pulsed-laser excitation and ionization and are detected by applying the thermionic diode technique. The measured total cross sections show pronounced structures near the ionization threshold, which can partly be associated with recent calculations performed by Bartschat and McLaughlin [J. Phys. B 23, L439 (1990)] and which are in excellent agreement with the calculation of Greene and Theodosiou [Phys. Rev. A 42, 5773 (1990)]. The absolute scales are also comparable. Our revised threshold value of 80 Mb is in sufficient agreement with their theoretical values, 120 and 100 Mb, respectively.