We present a measurement of the branching fractions for decay from the long-lived $5{D}_{5/2}$ level in ${^{138}\mathrm{Ba}}^{+}$ . The branching fraction for decay into the $6{S}_{1/2}$ ground state was found to be $0.846{(25)}_{\mathrm{stat}}{(4)}_{\mathrm{sys}}$ . We also report an improved measurement of the $5{D}_{5/2}$ lifetime, ${\ensuremath{\tau}}_{5{D}_{5/2}}=31.2(0.9)$ s. Together these measurements provide an experimental determination of transition rates for decay out of the $5{D}_{5/2}$ level. The low ($<7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}$ Torr) pressure in the ion trap in which these measurements were made simplified data acquisition and analysis. Comparison of the experimental results with theoretical predictions of the transition rates shows good agreement.We present a measurement of the branching fractions for decay from the long-lived $5{D}_{5/2}$ level in ${^{138}\mathrm{Ba}}^{+}$. The branching fraction for decay into the $6{S}_{1/2}$ ground state was found to be $0.846{(25)}_{\mathrm{stat}}{(4)}_{\mathrm{sys}}$. We also report an improved measurement of the $5{D}_{5/2}$ lifetime, ${\ensuremath{\tau}}_{5{D}_{5/2}}=31.2(0.9)$ s. Together these measurements provide an experimental determination of transition rates for decay out of the $5{D}_{5/2}$ level. The low ($<7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}$ Torr) pressure in the ion trap in which these measurements were made simplified data acquisition and analysis. Comparison of the experimental results with theoretical predictions of the transition rates shows good agreement.

arXiv:1409.0873Physical Review ADec 17, 201426 citations

LONG-LIVED EXCITED STATES IN IONS.

B. R. Turner, R. F. Mathis, J. A. Rutherford

Oct 31, 19680 citations

Spectroscopy of autoionizing states using state-selective ion detection

G. T. Xu, Xinqiang Wang, William E. Cooke

The authors have measured the population in each of the 5d 3/2 (m j ) ion states following autoionization of the (6p 3/2 nd) J=MJ=3 state by using a circularly polarized laser to excite the Ba + 5d 3/2 to 6p 1 2/ transition, and observing the polarized fluorescence of the Ba + 6p 1/2 to 6s 1/2 transition. The branching ratios for autoionization into each of the 5d 3/2 in l j channels can be related to these ion populations by using angular momentum algebra. The fractions of ions found in the m j =+3/2, +1/2, -1/2 and -3.2 state of the 5d 3/2 ion states were 5.9(+or-2.6)%, 4.5(+or-1.9)%, 3.2(+or-1.3)% and 1.9(+or-0.6)% respectively. This method can easily be generalized to measure the branching ratio for autoonization into other ion states.The authors have measured the population in each of the 5d 3/2 (m j ) ion states following autoionization of the (6p 3/2 nd) J=MJ=3 state by using a circularly polarized laser to excite the Ba + 5d 3/2 to 6p 1 2/ transition, and observing the polarized fluorescence of the Ba + 6p 1/2 to 6s 1/2 transition. The branching ratios for autoionization into each of the 5d 3/2 in l j channels can be related to these ion populations by using angular momentum algebra. The fractions of ions found in the m j =+3/2, +1/2, -1/2 and -3.2 state of the 5d 3/2 ion states were 5.9(+or-2.6)%, 4.5(+or-1.9)%, 3.2(+or-1.3)% and 1.9(+or-0.6)% respectively. This method can easily be generalized to measure the branching ratio for autoonization into other ion states.

Journal of Physics B Atomic Molecular and Optical PhysicsMar 14, 19932 citations

Relaxation of Long-Lived Atomic States.

Thad Gilbert Walker

Dec 1, 19880 citations

Oscillator Strengths of Ca II, Sr II, and Ba II

Alan C. Gallagher

The lifetimes of the $5p^{2}P_{\frac{3}{2}}$ and $5p^{2}P_{\frac{1}{2}}$ states of ${\mathrm{Sr}}^{+}$ and the $6p^{2}P_{\frac{3}{2}}$ and $6p^{2}P_{\frac{1}{2}}$ states of ${\mathrm{Ba}}^{+}$ have been measured by the Hanle-effect technique with optical excitation from the ion ground state. (The lifetimes of the ${\mathrm{Mg}}^{+}$ $3p^{2}P_{\frac{3}{2}}$ and ${\mathrm{Ca}}^{+}$ $4p^{2}P_{\frac{3}{2}}$ states were obtained by the same technique and reported previously.) These ${\mathrm{Ca}}^{+}$ , ${\mathrm{Sr}}^{+}$ , and ${\mathrm{Ba}}^{+}$ states each decay to a $^{2}D_{\frac{3}{2},\frac{5}{2}}$ doublet as well as to the ground $^{2}S_{\frac{1}{2}}$ state, and the branching ratios for these transitions have been measured. The ions were produced by introducing traces of the atomic vapor into an argon discharge. Consequently, the cross sections for collisional depolarization of these $^{2}P_{J}$ states due to collisions with argon were also obtained from the measurements. The experimental results are given in Tables I and II. A discussion of the ion-atom collisional depolarization cross sections is included.The lifetimes of the $5p^{2}P_{\frac{3}{2}}$ and $5p^{2}P_{\frac{1}{2}}$ states of ${\mathrm{Sr}}^{+}$ and the $6p^{2}P_{\frac{3}{2}}$ and $6p^{2}P_{\frac{1}{2}}$ states of ${\mathrm{Ba}}^{+}$ have been measured by the Hanle-effect technique with optical excitation from the ion ground state. (The lifetimes of the ${\mathrm{Mg}}^{+}$ $3p^{2}P_{\frac{3}{2}}$ and ${\mathrm{Ca}}^{+}$ $4p^{2}P_{\frac{3}{2}}$ states were obtained by the same technique and reported previously.) These ${\mathrm{Ca}}^{+}$, ${\mathrm{Sr}}^{+}$, and ${\mathrm{Ba}}^{+}$ states each decay to a $^{2}D_{\frac{3}{2},\frac{5}{2}}$ doublet as well as to the ground $^{2}S_{\frac{1}{2}}$ state, and the branching ratios for these transitions have been measured. The ions were produced by introducing traces of the atomic vapor into an argon discharge. Consequently, the cross sections for collisional depolarization of these $^{2}P_{J}$ states due to collisions with argon were also obtained from the measurements. The experimental results are given in Tables I and II. A discussion of the ion-atom collisional depolarization cross sections is included.

Physical ReviewMay 5, 1967217 citations

We present a measurement of the branching fractions for decay from the long-lived

5{D}_{5/2}

level in

{^{138}\mathrm{Ba}}^{+}

. The branching fraction for decay into the

6{S}_{1/2}

ground state was found to be

0.846{(25)}_{\mathrm{stat}}{(4)}_{\mathrm{sys}}

. We also report an improved measurement of the

5{D}_{5/2}

lifetime, ${\ensuremath{\tau}}_{5{D}_{5/2}}=31.2(0.9)$ s. Together these measurements provide an experimental determination of transition rates for decay out of the

5{D}_{5/2}

level. The low ($<7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}$ Torr) pressure in the ion trap in which these measurements were made simplified data acquisition and analysis. Comparison of the experimental results with theoretical predictions of the transition rates shows good agreement.

The lifetimes of the

5p^{2}P_{\frac{3}{2}}

and

5p^{2}P_{\frac{1}{2}}

states of

{\mathrm{Sr}}^{+}

and the

6p^{2}P_{\frac{3}{2}}

and

6p^{2}P_{\frac{1}{2}}

states of

{\mathrm{Ba}}^{+}

have been measured by the Hanle-effect technique with optical excitation from the ion ground state. (The lifetimes of the

{\mathrm{Mg}}^{+}

3p^{2}P_{\frac{3}{2}}

and

{\mathrm{Ca}}^{+}

4p^{2}P_{\frac{3}{2}}

states were obtained by the same technique and reported previously.) These

{\mathrm{Ca}}^{+}

{\mathrm{Sr}}^{+}

, and

{\mathrm{Ba}}^{+}

states each decay to a

^{2}D_{\frac{3}{2},\frac{5}{2}}

doublet as well as to the ground

^{2}S_{\frac{1}{2}}

state, and the branching ratios for these transitions have been measured. The ions were produced by introducing traces of the atomic vapor into an argon discharge. Consequently, the cross sections for collisional depolarization of these

^{2}P_{J}

states due to collisions with argon were also obtained from the measurements. The experimental results are given in Tables I and II. A discussion of the ion-atom collisional depolarization cross sections is included.