Showing papers by "Alfred S. Schlachter published in 2010"
TL;DR: In this article, 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.
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.
26 citations
TL;DR: In this article, most of the observed resonances associated with multiple Rydberg series of autoionizing states have been assigned spectroscopically using the quantum defect form of the Rydinger formula, guided by relativistic Hartree-Fock calculations of resonance energies and oscillator strengths.
Abstract: was measured to be 67.063 ± 0.015 eV, which is 0.207 eV lower than the value tabulated in the NIST database. Most of the observed resonances associated with multiple Rydberg series of autoionizing states have been assigned spectroscopically using the quantum defect form of the Rydberg formula, guided by relativistic Hartree-Fock calculations of resonance energies and oscillator strengths. Intermediate coupling R-matrix calculations performed using the semi-relativistic Breit-Pauli approximation are in suitable agreement with measured absolute photoionization cross section in the energy range studied for this complex Cl-like ion species.
13 citations
TL;DR: In this article, high-resolution photoionization experiments were carried out using beams of Be-like C 2+, N 3+ and O 4+ ions with roughly equal populations of the 1 S ground state and the 3 P o manifold of metastable components.
Abstract: High-resolution photoionization experiments were carried out using beams of Be-like C 2+ ,N 3+ and O 4+ ions with roughly equal populations of the 1 S ground state and the 3 P o manifold of metastable components. The energy scales of the experiments are calibrated with uncertainties of 1–10 meV depending on photon energy. Resolving powers beyond 20 000 were reached allowing for the separation of contributions from the individual metastable 3 P o, 3 P o and 3 P o states. The measured data compare favourably with semi-relativistic Breit–Pauli R-matrix calculations. (Some figures in this article are in colour only in the electronic version)
10 citations