| 1. |
- Chartkunchand, K. C., et al.
(author)
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Lifetimes of bound excited states of Pt-
- 2017
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In: Journal of Physics: Conference Series, Vol. 875, no. 022051. - : IOP Publishing. - 1742-6588.
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Conference paper (peer-reviewed)abstract
- Measurements of the radiative lifetimes of the two excited states of the platinum anion Pt- are presented. Pt- ions stored in the cryogenic ion storage ring DESIREE were photodetached at different photon wavelengths and the resulting yield of neutral Pt measured as a function of time was recorded. Analysis of the neutral decay curves show a 2.54 +/- 0.10 s lifetime for the higher-lying 5d(10)6(s) S-2(1/2) excited state and a lifetime in the range of 50-200 ms for the lower- lying 5d(9)6(s)(2) D-2(3/2) excited state. This is the first study to report the lifetime of a bound anion excited state with an electron configuration different from that of the anion ground state.
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| 2. |
- Chartkunchand, C, et al.
(author)
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Measuring the 2D3/2 Ni− excited state lifetime in DESIREE
- 2015
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Conference paper (peer-reviewed)abstract
- Experimental studies of the radiative lifetime of the sole excited state in the nickel anion are presented. Beams of Ni− stored in DESIREE at cryogenic temperatures were subject to photodetachment at different photon energies and the resulting neutrals collected. Preliminary analysis of the decay in neutral production yields a radiative lifetime of approximately 15 seconds for the 3d94s2 2D3/2 excited state.
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| 3. |
- Engstrom, L., et al.
(author)
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A new measurement of the 1s2s2p 4p0-1s2p2 4p transitions in c iv : Wavelengths, fine structure intervals and lifetimes
- 1987
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In: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 36:2, s. 250-254
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Journal article (peer-reviewed)abstract
- The n = 0 transition multiplet connecting the lowest quartet states of doubly excited C IV has been studied by beam-foil spectroscopy. The fine structure splittings obtained for the 1s2s2p 4p0and 1s2p2 4p terms confirm previous experimental results with an improved accuracy. The average transition wavelength = (1344.49 0.04)A is now more precisely determined by about a factor of eight. At the new level of precision this value shows a small but significant deviation from the best theoretical predictions. The lifetimes of the 1s2p2 4p levels have been determined as = (0.71 0.07)ns for 4P5/2 and = (1.66 0.13)ns for 4p3/2. The latter value disagrees with previous experimental results but is in excellent agreement with an isoelectronic trend analysis.
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Kaminska, M, et al.
(author)
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Storing keV negative ions for hours: Lifetime measurements in new time domains
- 2015
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Conference paper (peer-reviewed)abstract
- We have used one of the cryogenic ion storage rings of DESIREE to measure the lifetime of the 2P o 1/2 level in the sulfur anion to be 503 ± 43 seconds. This is orders of magnitude longer than any previously measured lifetime in a negatively charged ion.
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| 9. |
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| 10. |
- Andersson, Pontus, 1971, et al.
(author)
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Radiative lifetimes of metastable states of negative ions
- 2006
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In: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622 .- 2469-9926 .- 2469-9934. ; 73, s. 032705-
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Journal article (peer-reviewed)abstract
- We present a technique for measuring the radiative lifetimes of metastable states of negative ions that involves the use of a heavy-ion storage ring. The method has been applied to investigate the radiative decay of the np(3) P-2(1/2) levels of Te-(n=5) and Se-(n=4) and the 3p(3) D-2 state of Si- for which the J=3/2 and 5/2 levels were unresolved. All of these states are metastable and decay primarily by emission of E2 and M1 radiation. Multi Configuration Dirac-Hartree-Fock calculations of rates for the transitions in Te- and Se- yielded lifetimes of 0.45 s and 4.7 s, respectively. The measured values agree well with these predicted values. In the case of the D-2 state of Si-, however, our measurement was only able to set a lower limit on the lifetime. The upper limit of the lifetime that can be measured with our apparatus is set by how long the ions can be stored in the ring, a limit determined by the rate of collisional detachment. Our lower limit of 1 min for the lifetime of the D-2 state is consistent with both the calculated lifetimes of 162 s for the D-2(3/2) level and 27.3 h for the D-2(5/2) level reported by O'Malley and Beck and 14.5 h and 12.5 h, respectively, from our Breit-Pauli calculations.
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