Photoabsorption spectrum of Be^+

The absorption spectrum of the ion Be+ has been recorded in the vacuum ultraviolet by utilizing the method of two laser-produced plasmas. The photoionization cross sections of the outer electron for transitions of the type 2s–∊p and 2p–∊d have been measured at threshold; the values are σ = (1.5 ± 0.1) × 10−18 cm2 and σ = (2.5 ± 0.5) × 10−18 cm2, respectively. The inner-shell transitions lying in the region 90–105 Å have been measured and completely identified.