FINE-STRUCTURE AND ISOTOPE SHIFT STUDIES OF NATURAL ERBIUM USING LASER OPTOGALVANIC SPECTROSCOPY

The fine structure spectra of Er are being reported in the range 6320-5660 Angstrom A. A total of 109 lines have been observed. The wavelength analysis shows 80 new lines. Classifications of 41 new lines are being provided, using the known energy levels. Comparison of intensities of spectral lines at two different currents (5 and 10 mA) is discussed. The isotope shift measurements in 9 spectral lines of ErI are also presented. Based on the observed structure and magnitude of the isotope shifts, these lines are divided into four classes. Isotope shifts for five lines are being reported for the first time.