Zirconium isotope shift measurement using laser pumping and optogalvanic detection

This paper presents the results of attempts to increase the population of the excited levels by the laser pumping of zirconium atoms, using retroreflection of pump and probe beams. Measurements of the even isotope shifts are carried out for eight zirconium transitions between odd levels near 28000 cm-1 and four e5F levels above 35000 cm-1. A technique allowing the sub-Doppler isotope shift measurement without intermodulation which can be applied to weak lines, is also proposed.