Level-Crossing Spectroscopy in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>7</mml:mn><mml:mi /><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>S</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>2</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math>Thallium. I. Studies of Coherence-Narrowing, Collision-Broadening, and Buffer-Gas Effects

Radiative lifetimes of 15 Tl I levels belonging to the 6s 2 ns 2 S 1/2 (n = 7-14) and 6s 2 nd 2 D 3/2 Rydberg series (n = 6-12) have been measured using a time-resolved laser-induced fluorescence technique. All the measured levels have been excited from the ground state 6s 2 6p 2 P 0 1/2 (odd parity) with a single-step excitation process. The general perturbation of the ns series by the 6s6p 2 configuration and the corresponding modification of the lifetimes are adequately reproduced by a theoretical model including core-polarization effects and combined with a least-squares fit to the observed energy levels. The general behaviour of the lifetime values for the 6s 2 np odd levels along the Rydberg series is also well reproduced. The use of the multiconfiguration quantum defect theory has allowed us to obtain lifetime values along the 6s 2 ns 2 S 1/2 series up to levels with n = 31.

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“…k Demtröder (1962): phase-shift method. l Hsieh and Baird (1972): level crossing. m Gough and Griffiths (1977): Hanle effect.…”

Section: Discussion Of the Resultsmentioning

confidence: 99%

Lifetimes along perturbed Rydberg series in neutral thallium

Biémont

Palmeri

Quinet

et al. 2005

J. Phys. B: At. Mol. Opt. Phys.

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“…Shimon and Erdevdi 16 7.2 6 0.6 ns Lindgård et al 17 6.5 6 0.7 ns Gough and Griffiths 20 6.8 6 0.4 ns Anderson and Sorensen 14 7.6 6 0.5 ns 13 7.6 6 0.2 and 7.4 6 0.3 ns Penkin and Shabanova 22 8.25 6 0.6 ns Lawrence et al 23 8.1 6 0.8 ns Norton and Gallagher 24 7.45 6 0.2 ns Cunningham and Link 15 7.65 6 0.2 Anderson and Sorensen 14 7.7 6 0.5 ns Shimon and Erdevdi1 6 7.4 6 0.5 ns Harvey et al 25 7.8 6 0.3 ns Lindgård et al 17 6.9 6 1.0 and 6.3 6 0.7 ns Hsieh and Baird 26 7.55 6 0.08 ns Rebolledo et al 27 7.61 6 0.16 ns Biémont et al 18 7.3 6 0.4 ns Calculated 7.52 ns Present work 7.7 6 0.2 ns lifetime. The 276.787 nm laser pulse is followed by the 535.046 nm laser pulse, which is temporally controlled by the boxcar.…”

Section: Sourcementioning

confidence: 99%

Lifetime Measurements of Several S, P, and D States of Thallium in a Glow Discharge by Single-Step and Two-Step Laser-Excited Fluorescence

et al. 2008

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The lifetimes of several states in a thallium see-through hollow cathode discharge, or galvatron, are obtained to characterize its potential as an atomic line filter. The lifetimes of the thallium 6(2)D(3/2), 6(2)D(5/2), and 7(2)S(1/2) states are measured by time-resolved single-step laser-excited fluorescence by use of a 276.787 nm laser pulse or a 535.046 nm laser pulse and measuring the resulting fluorescence waveform at the appropriate wavelength. Values of 6.4 +/- 0.1, 7.5 +/- 1.1, and 7.7 +/- 0.2 ns were obtained for the 6(2)D(3/2), 6(2)D(5/2), and 7(2)S(1/2) states, respectively, which agree with values obtained by previous authors, as well as calculated values. No current dependence was observed for each of these states. The lifetime of the long-lived thallium 6(2)P(3/2) degrees metastable state was measured by two-step laser-excited fluorescence at various applied currents. The metastable level was pumped by a 276.787 nm laser pulse, and a temporally delayed 535.046 nm laser pulse interrogated the population of the metastable state. Relating the fluorescence intensity to the population of the metastable state as a function of delay time yielded a decay curve for the 6(2)P(3/2) degrees metastable state. Values of 2.1 +/- 0.2, 2.8 +/- 0.1, 3.1 +/- 0.3, 3.8 +/- 0.4, and 4.8 +/- 0.6 micros were found for applied currents of 14.0, 12.0, 10.0, 8.0, and 6.0 mA, respectively. The resulting lifetimes for the 6(2)P(3/2) degrees metastable state clearly show a dependence on the applied current and are expected to be due to collisions with the wall of the cathode, as well as a contribution due to collisions with electrons.

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“…As a result, the MBPT corrections that give the main contribution to the uncertainty budget are smaller leading to better agreement between the theoretical and experimental energy levels. Our values for the magnetic-dipole hfs constants and E1 transition amplitudes between low-lying levels in V NÀ1 potential are compared with experimental results [21][22][23] in Table II. The calculation of these properties was discussed in detail in Ref.…”

mentioning

confidence: 94%

Electric Dipole Moment Enhancement Factor of Thallium

2012

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The goal of this work is to resolve the present controversy in the value of the electric dipole moment (EDM) enhancement factor of Tl. We carry out several calculations by different high-precision methods, study previously omitted corrections, as well as test our methodology on other, parity conserving, quantities. We find the EDM enhancement factor of Tl to be equal to -573(20). This value is 20% larger than the recently published result of Nataraj et al. [Phys. Rev. Lett. 106, 200403 (2011)], but agrees very well with several earlier results.

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Level-Crossing Spectroscopy in7S2Thallium. I. Studies of Coherence-Narrowing, Collision-Broadening, and Buffer-Gas Effects

Cited by 28 publications

References 26 publications

Lifetimes along perturbed Rydberg series in neutral thallium

Lifetimes along perturbed Rydberg series in neutral thallium

Lifetime Measurements of Several S, P, and D States of Thallium in a Glow Discharge by Single-Step and Two-Step Laser-Excited Fluorescence

Electric Dipole Moment Enhancement Factor of Thallium

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