A beam-foil study of the 3s3p3d⁴Flevels in the Al-like ions of Ti, Fe and Ni

Abstract

The decays of the high angular momentum, high spin 4F0 states of the electron configuration 3s3p3d in aluminium-like ions (with three electrons outside a closed shell) have been identified in delayed spectra of foil excited Ti, Fe and Ni ion beams. The line identifications were aided by HXR, MCHF, and MCDF calculations and are corroborated by lifetime measurements which demonstrate the differential longevity of the fine structure levels. A search for the related case of ls2p3d4Fo level decays in Li-like ions of Si, P and S failed.

New atomic data for Ti X

“…In Fawcett's calculation, the 3s3p( 1 P)3d( 2 D o ) levels comes before the 3s3p( 1 P)3d( 2 P o ) levels, which are the reverse to NIST values. Further close comparison with the experimental results of Trabert [12] and Pinnington [13] are provided in Table A.…”

“…Laser produced plasma measurements have been performed for low lying, n = 3 levels of aluminum-like Ca VIII-Ni XVI by Redfors and Litzen [11]. A beam-foil experiment was carried out by Trabert [12] studying 3s3p3d 4 F levels of Ti X, Fe XIV, and Ni XVI. Pinnington [13] also performed a beam-foil experiment to study the lifetimes of the n = 3 complex in Al-like titanium, Ti 9+ .…”

M1/E2 transition rates in FeXthrough FeXIIImeasured at a heavy-ion storage ring

“…The Fe 13+ ion (spectrum Fe XIV) has two levels in the 3s 2 3p ground configuration (connected by the astrophysically useful 'green' corona line; the maximum J value is 3/2), various 3s3p 2 levels (among which the 4 P levels with their multi-nanosecond lifetimes are the longest-lived), and the relatively long-lived 3s3p3d 4 F o J levels. Lifetime values of two of the three 3s3p 2 4 P levels and of three of the four 3s3p3d 4 F o levels have been obtained by beamfoil spectroscopy (Träbert et al , 1993 We have already mentioned the problem of too little signal on the 530 nm line in comparison to the dark rate of the available photomultiplier. Thus the decay curve (with an integrated true signal above background of almost 10 5 counts) was dominated by the statistical fluctuations of the underlying integrated dark rate (of more than 10 6 counts within three decay times of the true light signal).…”

R -MATRIX ELECTRON-IMPACT EXCITATION OF Fe 13+ AND ITS APPLICATION TO THE SOFT X-RAY AND EXTREME-ULTRAVIOLET SPECTROSCOPY OF CORONA-LIKE PLASMAS

“…A portion is shown here for guidance regarding its form and content.) For some higher excited levels, such as 3s3p 24 P 1/2,5/2 and 3s3p3d 4 F o 3/2,5/2,7/2 , experimental data for the lifetimes are available in the works of Träbert et al (1988Träbert et al ( , 1993. A comparison of the lifetimes for the 3s3p 24 P 1/2,5/2 levels indicates that the present AS results are similar to the previous calcula- level, all theories are higher than the measurement by at least 60%.…”