Lifetimes of the metastable and levels in measured by laser probing of a stored ion beam

Lidberg, J.; Al-Khalili, A.; Norlin, L. O.; Royen, P.; Tordoir, Xavier; Mannervik, S.

doi:10.1088/0953-4075/32/3/017

Cited by 39 publications

(66 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our values are in agreement with the experiment for alkaline-earth ions within the uncertainties. Table III gives the comparisons of the present lifetime results with the experiment [23-26, 29, 33, 34, 44, 52-55] and with other theory [15,26,28,29,35,42,[42][43][44][45][46][47][48][49][50][51]. No …”

Section: Electric-quadrupole Transitionsmentioning

confidence: 71%

Forbidden M1 and E2 transitions in monovalent atoms and ions

Safronova

Johnson

2017

Phys. Rev. A

View full text Add to dashboard Cite

We carried out a systematic high-precision relativistic study of the forbidden magnetic-dipole and electric-quadrupole transitions in Ca + , Rb, Sr + , Cs, Ba + , Fr, Ra + , Ac 2+ and Th 3+ . This work is motivated by the importance of these transitions for tests of fundamental physics and precision measurements. The relative importance of the relativistic, correlation, Breit correction and contributions of negative-energy states is investigated. Recommended values of reduced matrix elements are presented together with their uncertainties. The matrix elements and resulting lifetimes are compared with other theoretical values and with experiment where available.

show abstract

Section: Electric-quadrupole Transitionsmentioning

confidence: 71%

Forbidden M1 and E2 transitions in monovalent atoms and ions

Safronova

Johnson

2017

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…The ultra-high vacuum (∼10 −11 mbar) makes collisons rare, and the metastable ions survive for a time comparable to several lifetimes. The laser probing technique (LPT) and its later developments have been decribed in a number of publications (Lidberg et al 1999;Mannervik 2003;Mannervik et al 2005). Here we only discuss the general idea of the technique and issues specific to the present measurement, and refer to previous publications for a more detailed description.…”

Section: Measurement Of Metastable Lifetimes In Sc IImentioning

confidence: 99%

The FERRUM project: experimental and theoretical transition rates of forbidden [Sc II] lines and radiative lifetimes of metastable Sc II levels

Hartman¹,

Gurell

Lundin

et al. 2008

A&A

View full text Add to dashboard Cite

Context. In many plasmas, long-lived metastable atomic levels are depopulated by collisions (quenched) before they decay radiatively. In low-density regions, however, the low collision rate may allow depopulation by electric dipole (E1) forbidden radiative transitions, so-called forbidden lines (mainly M1 and E2 transitions). If the atomic transition data are known, these lines are indicators of physical plasma conditions and used for abundance determination. Aims. Transition rates can be derived by combining relative intensities between the decay channels, so-called branching fractions (BFs), and the radiative lifetime of the common upper level. We use this approach for forbidden [Sc ii] lines, along with new calculations. Methods. Neither BFs for forbidden lines, nor lifetimes of metastable levels, are easily measured in a laboratory. Therefore, astrophysical BFs measured in Space Telescope Imaging Spectrograph (STIS) spectra of the strontium filament of Eta Carinae are combined with lifetime measurements using a laser probing technique on a stored ion-beam (CRYRING facility, MSL, Stockholm). These quantities are used to derive the absolute transition rates (A-values). New theoretical transition rates and lifetimes are calulated using the CIV3 code.Results. We report experimental lifetimes of the Sc ii levels 3d 2 a 3 P 0,1,2 with lifetimes 1.28, 1.42, and 1.24 s, respectively, and transition rates for lines from these levels down to 3d4s a 3 D in the region 8270−8390 Å. These are the most important forbidden [Sc ii] transitions. New calculations for lines and metastable lifetimes are also presented, and are in good agreement with the experimental data.

show abstract

“…Since the repopulation curve was recorded separately, a serious systematic error will appear if the repopulation curve is not properly normalized to the lifetime curve. In a previous work on lifetimes of the metastable levels in Ca II the measurements were performed during storage times that were eight times longer than the radiative lifetime of the metastable levels [13].…”

Section: Introductionmentioning

confidence: 99%