Radiative decay data for highly excited Zr I levels

Radiative lifetimes of 17 excited levels in Zr I, in the energy interval 29 000–40 974 cm−1, have been investigated using the time-resolved laser-induced fluorescence method. The levels belong to the 4d25s5p, 4d35p and 4d5s25p electronic configurations and were excited in a single-step process from either the ground term, 4d25s2 a 3F, or from the low-lying 4d25s2 a 3P and a 5F terms. For three levels, we confirm previous measurements while for 14 of the levels the lifetimes have been measured for the first time. The experimental results are compared to theoretical calculations performed with a multiconfiguration relativistic Hartree–Fock method including core-polarization effects. Theoretical transition probabilities of astrophysical interest, scaled by the experimental lifetimes, for the depopulating channels of the investigated levels are also presented.