Precise lifetime determination of the metastable 3d ² D _5/2 level in Ca ⁺ by "electron shelving"

Abstract

Ca + ions confined as a cloud in a Paul trap were excited and cooled by radiation from two lasers, tuned to the 4s 2 S 1/2 -4p 2 P 1/2 and 4p 2 P 1/2 -3d 2 D 3/2 transitions. The strong fluorescence of these lines disappears when we excite the ions simultaneously by a third laser on the 3d 2 D 3/2 -4p 2 P 3/2 line because of population trapping in the metastable 3d 2 D 5/2 state, into which the 4p 2 P 3/2 level decays. From the time dependence of the fluorescence after blocking the third laser we determined the lifetime of the 3d 2 D 5/2 level. Our result of τ = 1064(17) ms improves earlier results and agrees with the value recently computed by Liaw using the Brueckner approximation.

Metastable level lifetimes from electron-shelving measurements with ion clouds and single ions

“…Nevertheless, we have also evaluated our data by using the least-squares minimization of the exponential fitting curve and have found (1088 ± 16) ms. This value in very good agreement with experimental values which IC [11] IC [12] QJ [13] IC [14] IC [15] IC [16] QJ [17] QJ [18] SR [19] QJ [20] QJ [21] IC this work QJ-lsf QJ-mle [2] [3]…”

“…IC [12] QJ [13] IC [14] IC [15] IC [16] QJ [17] QJ [18] SR [19] QJ [20] QJ [ have been determined in the past by least-squares methods [18,19] with comparable number of events and probability distributions. One of the causes generating the discrepancy between these earlier values and recent measurements [20,21] as well as our value τ QJ = (1152 ± 20) ms could thus possibly be the choice of the data processing method, which may account for differences of a couple of percent depending on the number of considered quantum jumps per run.…”

“…There have been various theoretical approaches to the low-lying metastable doublet levels of 40 Ca + which have generated somewhat dispersed metastable lifetime predictions [2,3,4,5,6,7,8,9,10]. In the past decade the lifetimes of the metastable D-levels of the singlyionized calcium have also been measured several times [11,12,13,14,15,16,17,18,19,20,21]. Most of these measurements have been carried out in rf traps, showing a clear evolution towards longer lifetimes throughout the years, as error sources have been identified.…”

Combined experimental and theoretical probe of the lifetime of the3d2D5/2state in40Guan1, Shao2, Yuan3 et al. 2015Phys. Rev. A166110View full textAdd to dashboardCite

“…For example, in an early experiment on an ion cloud without laser cooling, Arbes et al obtained r3d5/2 = 1.154(61) s [19], which does not agree with Knoop et al's result of 0.994(38) s [20]. However, applying laser cooling technology to the ion cloud, Knoop et al's improved result [28] and Gudjons et al's result [21] agreed with each other and, also, agreed with the measurement conducted on the stored ion beam [22]. While experiments on single ions or ion chains with few ions can provide more suitable physical conditions to reduce collisional excitations and de-excitations as much as possible, such measurements have provided different values with smaller systematics.…”

Lifetime measurement of the metastable3dD5∕22state in theStaanum1, Jensen2, Martinussen3 et al. 2004Phys. Rev. A304211View full textAdd to dashboardCite

“…Finally, in astronomy, the 2 D 5/2 state has been used in a study of the β pictoris disk [5], and it is also commonly used in the study of Seyfert 1 galaxies and T Tauri stars [6]. As a consequence, the natural lifetime of the 2 D 5/2 state has attracted much attention in recent years, but unfortunately the results of the many measurements [3,7,8,9,10,11,12,13,14] and theoretical calculations [1,6,15,16,17,18,19] of the lifetime are scattered over a rather broad range (see Fig. 1 in Ref.…”