<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">He</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>2<i>p</i>state lifetime by a quenching-asymmetry measurement

Drake, G. W. F.; Kwela, J.; Wijngaarden, A. van

doi:10.1103/physreva.46.113

Cited by 28 publications

(15 citation statements)

References 15 publications

(20 reference statements)

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“…Also, a noteworthy measurement in one-electron systems is the lifetime of the 2p 1/2 level in He II at 99.717 ± 0.075 ps, which is in excellent agreement with theory (99.6891 ps) thus confirming basic radiation theory at the 0.075% level [89].…”

Section: H Sequencesupporting

confidence: 68%

AtomPy: An Open Atomic Data Curation Environment for Astrophysical Applications

Mendoza

Boswell

Ajoku

et al. 2014

Atoms

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We present a cloud-computing environment, referred to as AtomPy, based on Google-Drive Sheets and Pandas (Python Data Analysis Library) DataFrames to promote community-driven curation of atomic data for astrophysical applications, a stage beyond database development. The atomic model for each ionic species is contained in a multi-sheet workbook, tabulating representative sets of energy levels, A-values and electron impact effective collision strengths from different sources. The relevant issues that AtomPy intends to address are: (i) data quality by allowing open access to both data producers and users; (ii) comparisons of different datasets to facilitate accuracy assessments; (iii) downloading to local data structures (i.e., Pandas DataFrames) for further manipulation and analysis by prospective users; and (iv) data preservation by avoiding the discard of outdated sets. Data processing workflows are implemented by means of IPython Notebooks, and collaborative software developments are encouraged and managed within the GitHub social network. The facilities of AtomPy are illustrated with the critical assessment of the transition probabilities for ions in the hydrogen and helium isoelectronic sequences with atomic number Z ≤ 10.

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Section: H Sequencesupporting

confidence: 68%

AtomPy: An Open Atomic Data Curation Environment for Astrophysical Applications

Mendoza

Boswell

Ajoku

et al. 2014

Atoms

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“…Another high-accuracy experiment that sheds light on the size of radiative corrections is the measurement of the He + lifetime by Drake, Kwela, and Wijngaarden [41]. This experiment quotes an error of 0.075%, and agrees with a theoretical decay rate that does not include QED.…”

Section: Future Prospectsmentioning

confidence: 48%

Relativistic Calculations of Transition Amplitudes in the Helium Isoelectronic Sequence

Johnson

Plante

Sapirstein

1995

Advances in Atomic, Molecular, and Optical Physics

196

171

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Exact relativistic wave functions for n=1 and n=2 states of heliumlike ions are used to calculate single-photon transition amplitudes for 2 S0.Particular attention is given to the role of negative-energy states in bringing length and velocity forms into agreement, and related quantum electrodynamics issues. This is a reprinted version of an article with the same title published in Advances in Atomic, Molecular and Optical Physics 35, 225-329 (1995). Figures included in the original article are omitted here.

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“…The best agreement between theory and experiment in atomic lifetimes occurs in light atoms, with agreement at the 0.075% level in He + [20] where the atomic wave functions are exactly known, even approaching the 0.02% level in Li where the theoretical uncertainty is stated to be 1 × 10 −6 [21]. Only recently has a comparison approaching the 0.1% level in heavy alkali atoms become possible due to advances in relativistic manybody perturbation theory such as the all-order method [5,6,22].…”

Section: Introductionmentioning

confidence: 82%

Lifetime measurement of the cesium6P3/2level using ultrafast pump-probe laser pulses

et al. 2015

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Using the inherent timing stability of pulses from a mode-locked laser, we have precisely measured the cesium 6P 3/2 excited state lifetime. An initial pump pulse excites cesium atoms in two counterpropagating atomic beams to the 6P 3/2 level. A subsequent synchronized probe pulse ionizes atoms which remain in the excited state, and the photo-ions are collected and counted. By selecting pump pulses which vary in time with respect to the probe pulses, we obtain a sampling of the excited state population in time, resulting in a lifetime value of 30.462(46) ns. The measurement uncertainty (0.15%) is slightly larger than our previous report of 0.12% [Phys. Rev. A 84, 010501(R) (2011)] due to the inclusion of additional data and systematic errors. In this follow-up paper we present details of the primary systematic errors encountered in the measurement, which include atomic motion within the intensity profiles of the laser beams, quantum beating in the photo-ion signal, and radiation trapping. Improvements to further reduce the experimental uncertainty are also discussed.

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He+2pstate lifetime by a quenching-asymmetry measurement

Cited by 28 publications

References 15 publications

AtomPy: An Open Atomic Data Curation Environment for Astrophysical Applications

AtomPy: An Open Atomic Data Curation Environment for Astrophysical Applications

Relativistic Calculations of Transition Amplitudes in the Helium Isoelectronic Sequence

Lifetime measurement of the cesium6P3/2level using ultrafast pump-probe laser pulses

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