The second spectrum of krypton

The second spectrum of krypton (Kr n) characteristic of once ionized krypton atoms (Kr+) has been selected from various krypton spectra excited in Geissler tubes by noting intensity changes accompanying variations of capacity and inductance in the electrical circuit. This description and analysis of the Kr n spectrum includes estimates of relative intensities and wave-length measurements for 1,050 lines extending from 2,080.53 A in the ultraviolet to 10,659.5 A in the infrared. Most of these lines (71 percent) have been classified as combinations of 128 energy levels, 112 of which have been more or less definitely identified with quantum numbers and electron configurations. Zeeman effects are quoted for 102 lines. In addition, 51 lines in the extreme ultraviolet (575.92 to 964.93 A) are classified as transitions from excited states to the normal ones. The sp electron configuration of the normal Kr+ ion is represented by a doublet P term with level separation 5,371 cm , and the excited states are described by doublet and quartet terms arising from the addition of ns, np, nd, nf electrons to the sp group constituting the outer structure of the doubly charged ion (Kr++). An absolute value of 198,182 cm is derived for the ground level s2p 5 . P§/4, which fixes the ionization potential of Kr+ atoms at approximately 24.4 volts. CONTENTS Page