Photoionization of singly and doubly charged neon ions following inner-shell excitation

Photoion yields from Ne⁺ to Ne²⁺ and from Ne²⁺ to Ne³⁺ were measured near the K-shell (1s-2p) autoionizing resonance region in the 841--858-eV and 850--863-eV photon energy range, respectively. Measurements were performed using a photon-ion merged-beam apparatus with an electron cyclotron resonance ion source. Multiconfiguration Dirac-Fock calculations were performed to interpret the experimental results. The calculations show fairly good agreement with the experimental results. Isonuclear series for the photoionization of Ne⁺, Ne²⁺, and Ne³⁺ are discussed.