Lifetime measurements obtained by the beam-foil method are given for 13 levels in In II and 12 levels in In III. Particular attention has been paid to cascade correction with the application of a new arbitrarily normalized decay curves (ANDC) program. The results are compared with theory, and good agreement is found with recent multiconfiguration relativistic Hartree–Fock (MCRHF) calculations for the In II resonance transition. The results for 2P and 2D levels in In III and 1D levels in In II indicate a need for further calculations.

Beam-foil intensity decay curves for transitions in the wavelength range 750–5250 Å are used to derive the lifetimes of the 6s1S, 5p1P, 6p1P, 5d1D, 6d1D, 5p21D, 4f1F, 6s3S, 6p3p, 5p23p, 5d3D, 6d3D, and 4f3F levels of Sn III, and of the 6s2S, 5p2P, 6p2P, 5d2D, 6d2D, 4d95 s22D, and 4f2F levels of Sn IV. The arbitrarily normalized decay-curve analyses are used for most levels. Good agreement is found between experiment and a recent (relativistic Hartree–Fock + core-polarization) calculation for the resonance transition in low-Z members of the Cd 1 isoelectronic sequence, but the experimental f values are found to lie systematically about 20% above the theoretical trend obtained from a similar calculation for the Ag I sequence. Configuration interaction is found to produce very different lifetimes for the two 4d95s22D levels of Sn IV, and the energy of the J = 3/2 level is determined to be 177 060 ± 50 cm−1.

Levels of Ca ions with one, two or four electrons in the n = 3 shell have been studied for their decay properties and lifetimes. For the 3p 2 P o 1/2,3/2 levels of Ca X and the 3s3p 1 P o 1 level of Ca IX, arbitrarily normalized decay curve (ANDC) and cascade model analyses yield results with precisions of 10% and less and with low systematic uncertainties. The measured lifetime of the Ca IX 3s3d 1 D 2 level confirms the need to include relativistic effects in the calculation. The lifetime results are compared to other, experimental and theoretical, data available for the isoelectronic sequences.

Beam-foil intensity decay curves for transitions in the wavelength range from 900 to 2200 Å are used to derive the lifetimes of the 6s6p1P1 and 3P1 6s6d1D2, 6s7s1S0, and 6p21D2 levels of Pb III, and the 6p2P1/2 and 2P3/2, 6d2D3/2 and 2D5/2, 7s2S1/2, and 5d96s22D3/2 levels of Pb IV, arbitrarily normalized decay curve (ANDC) analyses being used for the 6s6p and 6p levels. In the case of the two 6s6p levels studied in Pb III, good agreement is found with a recent calculation in which a polarization model accounts for valence–core correlation. However, the agreement between the lifetimes observed for the 6p levels in Pb IV and a similar, earlier calculation is only fair.

We have measured lifetimes for 24 terms in P I-P V using the beam-foil technique in the vacuum UV region. The results have been compared with theoretical calculations and with other experimental values. Several significant discrepancies with earlier results have been found. We present the first experimental lifetimes for 9 terms. Most of our lifetimes can be converted directly into f-values, and we discuss these in relation to trends along isoelectronic sequences. Configuration interaction is found to be important for several transitions. We also suggest a revision of the recently-determined abundance of phosphorus in interstellar clouds, based upon our new f-value for the 1 308 Å multiplet in P II.