Hyperfine structure of odd-parity levels in 91Zr 1

Hyperfine structures have been investigated for odd-parity 4d25s5p and 4d35p levels for six 91Zr 1 transitions in the spectral range 458-549 nm using Doppler-free saturated absorption spectroscopy in a sputtered vapour. The measured hyperfine structure constants, A and B, together with results of previous studies were analysed by means of a parametric method. The interpretation was based on refined multiconfigurational fine structure calculations, which include the main Rydberg series configuration states. The analysis suggests a drastic revision of the composition of the 4d5s25p configuration levels. The main one-electron hyperfine structure parameters for the lowest configuration, i.e. 4d25s5p, are determined to be a5s10 -2672(61) MHz, a4d01= -115.8(3.4) MHz, a5p01 = -127.4(3.7) MHz, b4d02 = -93.5(2.8) MHz and b5p02 = -139.9(5.1) MHz. These values are in excellent agreement with ab initio calculations, justifying our choice of the perturbing configuration states. (author)