Mean Lives Of Some 3p Levels Of Neon Ii

The mean lives of six 3p levels of singly ionized neon have been measured using the ionic beam method with a gas target. Relative line intensities in two of the strongest multiplets have also been measured. It was found that the levels were populated according to the weight 2J + 1, where J is the quantum number for the total electronic angular momentum. The levels and the measured lifetimes in nanoseconds are 3p(4)D (7 degrees /2) (7. 8 +/- 0. 5), (4)D (5 degrees /2) (7. 6 +/- 0. 1), (4)P (5 degrees /2) (10. 1 +/- 0. 4), (4)P (3 degrees /2) (10. 6 +/- 0. 4), (2)D (3 degrees /2) (8. 43 +/- 0. 07), and 3p'(2)F (7 degrees /2) (8. 5 +/- 0. 3). The indicated uncertainties are the standard deviations from the means; however, an additional uncertainty of approximately 10% should be added to each value in order to account for possible systematic errors. The reported lifetimes were obtained by fitting appropriate line intensities with the sum of two exponentials and a constant. Such fits adequately described the decay of the level populations of the fast Ne(+) ions downstream from the exit aperture of the differentially pumped collision cell.