K-shell photoionization of ground-state Li-like boron ions [B2 +]: experiment and theory

Abstract

Absolute cross sections for the K-shell photoionization of ground-state Li-like boron [B2 +(1s22s 2S)] ions were measured by employing the ion–photon merged-beams technique at the Advanced Light Source synchrotron radiation facility. The energy ranges 197.5–200.5 eV, and 201.9–202.1 eV of the [1s(2s2p)3P]2Po and [1s(2s2p)1P] 2Po resonances, respectively, were investigated using resolving powers of up to 17 600. The energy range of the experiments was extended to about 238.2 eV yielding energies of the most prominent [1s(2ℓ nℓ′)]2Po resonances with an absolute accuracy of the order of 130 ppm. The natural linewidths of the [1s(2s2p)3P] 2Po and [1s(2s2p)1P] 2Po resonances were measured to be 4.8 ± 0.6 meV and 29.7 ± 2.5 meV, respectively, which compare favourably with theoretical results of 4.40 meV and 30.53 meV determined using an intermediate-coupling R-matrix method.