An investigation of the structure near the L2,3edges of argon, the M4,5edges of krypton and the N4,5edges of xenon, using electron impact with high resolution

The authors have investigated structure near the L 2,3 edges of argon, the M 4,5 edges of krypton and the N 4,5 edges of xenon, using electron impact at an incident energy of 1.5 keV and with an energy resolution of typically 70 meV. The structure observed corresponds to the promotion, via an optically allowed or optically forbidden transition, of an electron from an inner shell of the atom to an unoccupied Rydberg orbital. The energies of these excited states have been obtained, enabling the accurate determination of the Rydberg series limits. The effective quantum numbers of the excited states have been found to be closely related to those of the 'equivalent-core' atoms K I, Rb I and Cs I.