Spectroscopic studies of neutral erbium in a hollow cathode lamp: Electronic temperature and two-step optogalvanic spectroscopy

This work reports the results obtained through spectroscopic studies developed on an erbium-neon hollow cathode lamp. First, emission spectra were obtained in order to estimate the electronic temperature of neutral erbium, which is an important plasma parameter for the calculation of atomic population in different energy levels. It was identified seven pairs of lines that can be used to estimate the electronic temperature of this metal by the two-line Boltzmann method. After these experiments, using the laser multistep excitation technique, three transitions for the first step excitation from the erbium ground state and eight transitions corresponding to the second step were observed. Four of these eight second steps correspond to erbium lines that were not reported in the literature before: 599.44 nm (17,157.31 → 33,844 cm− 1), 603.65 nm (17,073.80 → 33,635 cm− 1), 597.48 nm (17,029.06 → 33,761 cm− 1) and 597.56 nm (17,029.06 → 33,759 cm− 1).