[en] The Stokes parameters of light emitted following beam-foil excitation have been measured as a function of foil tilt angle from 0⁰ to 80⁰, in 5 degree increments, for the 2s ¹S - 3p ¹p⁰ and 2p ¹p⁰ - 4d ¹D transitions in He I. The curves so obtained are remarkably different for the two transitions. These measurements are an extension of a recently completed experiment which demonstrated the close agreement betwen the polarization parameters from the 2s - 3p and 2s - 4p transitions and between those from the 2p - 3d and 2p - 4d transitions

[en] The authors report a simple method for the production of useful beams of selenium and arsenic for 'beam-foil' studies. (Auth.)

[en] A review is presented of the current status of beam-foil lifetime measurements, with emphasis on the techniques now being used to correct for cascade effects. Examples of application of these technqiues are taken from work that has appeared since the Laval Conference of 1981. The ANDC method is shown to yield generally satisfactory results for one- and two-electron systems, but further work is needed to establish the best method for more complex systems. Brief discussions are also given of recent lifetime measurements for some moderately- and highly-ionized atoms, and of very recent measurements of an autoionization rate in neutral fluorine and a magnetic-dipole transition rate in hydrogen-like argon. A short summary of recent developments in heay metal ion sources is also presented. (orig.)

[en] We describe a simple method for measuring the velocity of a fast beam to within +- 1%, and discuss the factors which determine the accuracy of the measurement. (orig.)

No abstract available

[en] We have obtained cascade-free lifetimes for the 3d²4p z ⁴D⁰_5/2 level in Ti⁺ (4.01±0.06 ns), the 4p ²P⁰_1/2,3/2 levels in Ca⁺ (6.95±0.18 ns and 6.87±0.17 ns respectively) and the 2p⁵(²P⁰_3/2)3p[5/2]_J=3 level in Na⁺ (4.83±0.05 ns) using the beam-laser technique. These experiments demonstrate some possible variations of the beam-laser method. These results are compared with previous experiments and theory. (orig.)

[en] The Stokes parameters of light emitted following beam-foil excitation have been measured as a function of foil tilt angle from 0⁰ to 70⁰ for the 2s ¹S-3p ¹P/sup o/, 2s ¹S-4p ¹P/sup o/, 2p ¹P/sup o/-3d ¹D, and 2p ¹P/sup o/-4d ¹D transitions in He I. The precision of the measurements has been established using the 2p ¹P/sup o/-4s ¹S transition. A new method is described for analyzing beam--tilted-foil data. The results are compared with those forecast by the theory suggested by Band, and good agreement is found for the transitions from ¹P/sup o/ terms but somewhat poorer agreement is found for the transitions from ¹D terms. In particular, the M/I polarization is shown to become negative for a foil tilt angle of around 60⁰ in the case of the ¹P/sup o/ terms and 45⁰ for the ¹D terms, while the total polarization fraction remains nearly constant at all tilt angles observed for the ¹P/sup o/ terms but shows a pronounced minimum at about 45⁰ for the ¹D terms. A simple procedure is also outlined for the accurate determination of the phase of a retarder plate at any required wavelength

[en] We report the first beam-laser measurement of the lifetime of the 3p levels in Mg II. The measured lifetimes - 3.854±0.030 ns (j=1/2) and 3.810±0.040 ns (j=3/2) - agree closely with a recent calculation by Theodosiou and Curtis. We also report observations of both two-step and two-photon excitation of the 3d levels. (orig.)

[en] An ANDC analysis of beam-foil decay curves for the 4s-4p, 4p-4d and 4p-5s transitions in Ge IV yield 4p lifetimes 0.91 +- 0.05 ns (j = 1/2) and 0.82 +- 0.05 ns (j = 3/2) and hence a 4s-4p multiplet f value of 0.77 +- 0.05, in excellent agreement with MCHF and RHF (+core polarization) calculations. (orig.)

[en] An analysis of the beam-foil spectrum of argon at 1.6 MeV is used to suggest assignments for levels of the 3p³ and 3s3p3d electron configurations of Ar VI. Decay curves for transitions from these levels yield lifetimes that are generally about 30% longer than the values calculated by Fawcett. ANDC analyses incorporating these transitions are also used to estimate the lifetimes of the resonance doublet levels, which are found to be in good agreement with Fawcett's calculations for 3s3p²²S, ²D and 3s²3d ²D. (orig.)