Observation and identification of doubly excited KrI 4s²4p⁴5sn  Rydberg series

Dispersed Kr VUV-fluorescence excitation spectra and photoion yields were recorded in the exciting photon energy range between 28.4 eV and 28.7 eV with extremely narrow bandwidth (1.7 meV at 28.55 eV) of the monochromatized synchrotron radiation used as the exciting photon source. Two series of doubly excited KrI states were observed and identified as the 4s 2 4p 4 ( 3 P) 5s 4 P 1/2 n p and the 4s 2 4p 4 ( 3 P)5s 2 P 3/2 n p series.