Photoionization of \textit{Cl-} like \textit{K}$^{2+}$ and \textit{Ca}$^{3+}$

Absolute photoionization cross-section measurements have been performed for $K^{2+}$ and\textit{ Ca}$^{3+}$ in the energy range from the ionization thresholds of their metastable state ($^{2}P^{o}_{1/2})$ and ground state ($^{2}P^{o}_{3/2})$ to the series limit of the dominant Rydberg series of resonances. The measurements were performed using the Ion-Photon Beam endstation on Beam line 10.0.1 of the Advanced Light Source (ALS) by merging an ion beam with a beam of synchrotron radiation from an undulator magnet. The data are compared to previous measurements for \textit{Cl-}like \textit{Ar}$^{+}$ [1]. Most of the resonances have been characterized by multiple Rydberg series of autoionizing states and assigned spectroscopically using quantum defect form of Rydberg formula. The measurements are compared with R-matrix calculations and with relativistic Hartree-Fock calculations of the energies and the oscillator strengths of the autoionizing transitions. [1]: A. M. Covington et al, Proc. XX11 ICPEAC, 48 (2001).