Physical Review A

Two-step stabilization of autoionizing states

J. G. Story, L. D. Van Woerkom, William E. Cooke

Published Nov 1, 1986• 9 citations

Abstract

A two-step process using internal conversion and fluorescence to stabilize the $6{P}_{\frac{3}{2}}11d$ autoionizing state of barium has been observed. The internal conversion produces very highly excited autoionizing Rydberg states, which then emit fluorescence to produce singly excited, bound states. Inclusion of this process should bring calculations closer to agreement with recent measurements of dielectronic recombination.

DOI: 10.1103/physreva.34.4508

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Residual-ion orientation after autoionization

G. T. Xu, Xiao Wang, J. G. Story +1 more

Physical Review AApr 1, 19934 citations

Doubly Excited Autoionizing Rydberg States of Sr

William E. Cooke, Thomas F. Gallagher, S. A. Edelstein +1 more

Physical Review LettersJan 16, 1978296 citations

Short-pulse photoionization of perturbed Rydberg states: Laser-induced autoionization

Rutger B. Vrijen, J. H. Hoogenraad, Lambertus D. Noordam

Physical Review ASep 1, 19957 citations

Enhancement of the autoionization rate of two-photon excited states of Ba (6d_{5/2}nd_{5/2(3/2)})_{J=4} near the Ba^{+} 6d_{3/2} limit

Ravinder Kachru, N. Tran, H. B. van Linden van den Heuvell +1 more

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Rydberg and autoionizing states of neutral ytterbium

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Journal of Physics B Atomic Molecular and Optical PhysicsSep 14, 199422 citations

Laser-induced stabilization of autoionizing states

Heider N. Ereifej, J. G. Story

Stabilization of autoionizing states of barium by laser-induced, stimulated emission of light is demonstrated. Relative to purely flourescent stabilization, the data clearly show an enhancement of the stabilization process for laser pulses short compared to the flourescent lifetime of the autoionizing states. Shakeup spectra in which the principal quantum number of both electrons changes during the stimulated emission process are also clearly demonstrated.

Physical Review ANov 1, 19995 citations

Physical Review A

Two-step stabilization of autoionizing states

J. G. Story, L. D. Van Woerkom, William E. Cooke

Published Nov 1, 1986• 9 citations

Publisher

Abstract

A two-step process using internal conversion and fluorescence to stabilize the

6{P}_{\frac{3}{2}}11d

autoionizing state of barium has been observed. The internal conversion produces very highly excited autoionizing Rydberg states, which then emit fluorescence to produce singly excited, bound states. Inclusion of this process should bring calculations closer to agreement with recent measurements of dielectronic recombination.

DOI: 10.1103/physreva.34.4508

Related papers

Residual-ion orientation after autoionization

G. T. Xu, Xiao Wang, J. G. Story +1 more

We have measured the relative population in the two ${\mathit{m}}_{\mathit{j}}$ states of barium 6 ${\mathit{p}}_{1/2}$ ions produced by the autoionization of (6 ${\mathit{p}}_{3/2}$ nd ${)}_{\mathit{J}=\mathit{M}\mathit{J}}$ =3 states by detecting the helicity of the emitted fluorescence. These populations can be related to the relative branching ratio into the 6 ${\mathit{p}}_{1/2}$ \ensuremath{\epsilon} ${\mathit{d}}_{5/2}$ and 6 ${\mathit{p}}_{1/2}$ \ensuremath{\epsilon} ${\mathit{g}}_{7/2}$ continuum channels. Rydberg states with n=16--23 have similar branching ratios, producing approximately six times as much 6 ${\mathit{p}}_{1/2}$ \ensuremath{\epsilon} ${\mathit{d}}_{5/2}$ population as 6 ${\mathit{p}}_{1/2}$ \ensuremath{\epsilon} ${\mathit{g}}_{7/2}$ population.We have measured the relative population in the two ${\mathit{m}}_{\mathit{j}}$ states of barium 6${\mathit{p}}_{1/2}$ ions produced by the autoionization of (6${\mathit{p}}_{3/2}$nd${)}_{\mathit{J}=\mathit{M}\mathit{J}}$=3 states by detecting the helicity of the emitted fluorescence. These populations can be related to the relative branching ratio into the 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{d}}_{5/2}$ and 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{g}}_{7/2}$ continuum channels. Rydberg states with n=16--23 have similar branching ratios, producing approximately six times as much 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{d}}_{5/2}$ population as 6${\mathit{p}}_{1/2}$\ensuremath{\epsilon}${\mathit{g}}_{7/2}$ population.

Physical Review AApr 1, 19934 citations

Doubly Excited Autoionizing Rydberg States of Sr

William E. Cooke, Thomas F. Gallagher, S. A. Edelstein +1 more

We report the observation of doubly excited autoionizing Rydberg states of Sr, belonging to the configuration $5{p}_{\frac{1}{2}}$ , $\mathrm{nl}$ . Our procedure involves a three-step optical excitation process which incorporates Stark switching to reach higher $l$ states not normally accessible because of dipole selection rules. Quantum defects are reported for several $5{p}_{\frac{1}{2}}$ , $\mathrm{ns}$ and $5{p}_{\frac{1}{2}}$ , $\mathrm{nd}$ states. The lifetimes of the $5{p}_{\frac{1}{2}}$ , $\mathrm{ns}$ states are shown to scale as ${({n}^{*})}^{3}$ , and the lifetimes of the $5{p}_{\frac{1}{2}}$ , $16l$ states are shown to increase dramatically with increasing $l$ .We report the observation of doubly excited autoionizing Rydberg states of Sr, belonging to the configuration $5{p}_{\frac{1}{2}}$, $\mathrm{nl}$. Our procedure involves a three-step optical excitation process which incorporates Stark switching to reach higher $l$ states not normally accessible because of dipole selection rules. Quantum defects are reported for several $5{p}_{\frac{1}{2}}$, $\mathrm{ns}$ and $5{p}_{\frac{1}{2}}$, $\mathrm{nd}$ states. The lifetimes of the $5{p}_{\frac{1}{2}}$, $\mathrm{ns}$ states are shown to scale as ${({n}^{*})}^{3}$, and the lifetimes of the $5{p}_{\frac{1}{2}}$, $16l$ states are shown to increase dramatically with increasing $l$.

Physical Review LettersJan 16, 1978296 citations

Short-pulse photoionization of perturbed Rydberg states: Laser-induced autoionization

Rutger B. Vrijen, J. H. Hoogenraad, Lambertus D. Noordam

Laser-induced autoionization, a form of forced autoionization, is discussed. Highly excited atomic Rydberg states generally have a small cross section for photoionization due to their small overlap with the nucleus. The cross section for photoionization can be strongly enhanced if the Rydberg series is perturbed by an atomic state with a relatively large cross section for photoionization. The photoionization dynamics of such a perturbed Rydberg system shows strong similarities to that of an autoionizing Rydberg series. For intense laser pulses, which strongly couple the perturber to the continuum, the photoionization rate is limited by the coupling between the Rydberg states and the perturber or, in other words, the autoionization rate. The model describing this ionization dynamics is applied to the barium 6snd ${(}^{1,3}$ ${\mathit{D}}_{2}$ ) state which is perturbed by the 5d7d ${(}^{1}$ ${\mathit{D}}_{2}$ ) state. The calculations show good agreement with experimental results of photoionization of barium Rydberg states with subpicosecond laser pulses of light of 620 nm in wavelength.Laser-induced autoionization, a form of forced autoionization, is discussed. Highly excited atomic Rydberg states generally have a small cross section for photoionization due to their small overlap with the nucleus. The cross section for photoionization can be strongly enhanced if the Rydberg series is perturbed by an atomic state with a relatively large cross section for photoionization. The photoionization dynamics of such a perturbed Rydberg system shows strong similarities to that of an autoionizing Rydberg series. For intense laser pulses, which strongly couple the perturber to the continuum, the photoionization rate is limited by the coupling between the Rydberg states and the perturber or, in other words, the autoionization rate. The model describing this ionization dynamics is applied to the barium 6snd${(}^{1,3}$${\mathit{D}}_{2}$) state which is perturbed by the 5d7d${(}^{1}$${\mathit{D}}_{2}$) state. The calculations show good agreement with experimental results of photoionization of barium Rydberg states with subpicosecond laser pulses of light of 620 nm in wavelength.

Physical Review ASep 1, 19957 citations

Enhancement of the autoionization rate of two-photon excited states of Ba (6d_{5/2}nd_{5/2(3/2)})_{J=4} near the Ba^{+} 6d_{3/2} limit

Ravinder Kachru, N. Tran, H. B. van Linden van den Heuvell +1 more

We report the excitation of highly excited $6{d}_{\frac{5}{2}(\frac{3}{2})}\mathrm{nd}(\mathrm{ns})$ states of barium, which lie ~5.6 eV above the first ionization limit of Ba, using two-photon excitation from the bound $6snd(\mathrm{ns})$ Rydberg states. The two-photon excitation scheme requires rather modest laser power (~0.5 mJ), and the ${(6{d}_{\frac{5}{2}}n{d}_{j})}_{J=4}$ states exhibit a sharp enhancement in the autoionization rate beyond $n=25$ which is accompanied by the onset of ejection of very-low-energy electrons ( 0.02 eV). We observe that the ${6{d}_{\frac{5}{2}}n{d}_{j})}_{J=4}(n25)$ states predominantly autoionize to the nearly degenerate $6{d}_{(\frac{3}{2})}$ state of ${\mathrm{Ba}}^{+}$ . This result has important implications for the development of autoionization lasers and the phenomenon of dielectronic recombination.We report the excitation of highly excited $6{d}_{\frac{5}{2}(\frac{3}{2})}\mathrm{nd}(\mathrm{ns})$ states of barium, which lie ~5.6 eV above the first ionization limit of Ba, using two-photon excitation from the bound $6snd(\mathrm{ns})$ Rydberg states. The two-photon excitation scheme requires rather modest laser power (~0.5 mJ), and the ${(6{d}_{\frac{5}{2}}n{d}_{j})}_{J=4}$ states exhibit a sharp enhancement in the autoionization rate beyond $n=25$ which is accompanied by the onset of ejection of very-low-energy electrons ( 0.02 eV). We observe that the ${6{d}_{\frac{5}{2}}n{d}_{j})}_{J=4}(n25)$ states predominantly autoionize to the nearly degenerate $6{d}_{(\frac{3}{2})}$ state of ${\mathrm{Ba}}^{+}$. This result has important implications for the development of autoionization lasers and the phenomenon of dielectronic recombination.

Physical Review AJul 1, 198417 citations

Rydberg and autoionizing states of neutral ytterbium

C. B. Xu, Xiang-Yuan Xu, Wenbo Huang +2 more

In the study of Yb atomic Rydberg states, new members of 6sns 1 S 0 series for n=23, 24, 66-116 and 6snd 1 D 2 series for n=81-114 were observed. The data are in excellent agreement with the MQDT analysing results. The autoionizing Rydberg series 6p 1 2 /n's ( 1/2 , 1/2 ) 1 0 were investigated by three-step laser excitation. The ICE model was used to explain the experimental spectrum, and it has been proved to be suitable for describing the excitation of the autoionizing Rydberg states with a weakly-excited core.In the study of Yb atomic Rydberg states, new members of 6sns 1 S 0 series for n=23, 24, 66-116 and 6snd 1 D 2 series for n=81-114 were observed. The data are in excellent agreement with the MQDT analysing results. The autoionizing Rydberg series 6p 1 2 /n's ( 1/2 , 1/2 ) 1 0 were investigated by three-step laser excitation. The ICE model was used to explain the experimental spectrum, and it has been proved to be suitable for describing the excitation of the autoionizing Rydberg states with a weakly-excited core.

Journal of Physics B Atomic Molecular and Optical PhysicsSep 14, 199422 citations

Laser-induced stabilization of autoionizing states

Heider N. Ereifej, J. G. Story

Physical Review ANov 1, 19995 citations

A two-step process using internal conversion and fluorescence to stabilize the

6{P}_{\frac{3}{2}}11d

We have measured the relative population in the two

{\mathit{m}}_{\mathit{j}}

states of barium 6

{\mathit{p}}_{1/2}

ions produced by the autoionization of (6

{\mathit{p}}_{3/2}

{)}_{\mathit{J}=\mathit{M}\mathit{J}}

=3 states by detecting the helicity of the emitted fluorescence. These populations can be related to the relative branching ratio into the 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{d}}_{5/2}

and 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{g}}_{7/2}

continuum channels. Rydberg states with n=16--23 have similar branching ratios, producing approximately six times as much 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{d}}_{5/2}

population as 6

{\mathit{p}}_{1/2}

\ensuremath{\epsilon}

{\mathit{g}}_{7/2}

population.

We report the observation of doubly excited autoionizing Rydberg states of Sr, belonging to the configuration

5{p}_{\frac{1}{2}}

\mathrm{nl}

. Our procedure involves a three-step optical excitation process which incorporates Stark switching to reach higher

l

states not normally accessible because of dipole selection rules. Quantum defects are reported for several

5{p}_{\frac{1}{2}}

\mathrm{ns}

and

5{p}_{\frac{1}{2}}

\mathrm{nd}

states. The lifetimes of the

5{p}_{\frac{1}{2}}

\mathrm{ns}

states are shown to scale as

{({n}^{*})}^{3}

, and the lifetimes of the

5{p}_{\frac{1}{2}}

16l

states are shown to increase dramatically with increasing

l

{(}^{1,3}

{\mathit{D}}_{2}

) state which is perturbed by the 5d7d

{(}^{1}

{\mathit{D}}_{2}

) state. The calculations show good agreement with experimental results of photoionization of barium Rydberg states with subpicosecond laser pulses of light of 620 nm in wavelength.

We report the excitation of highly excited

6{d}_{\frac{5}{2}(\frac{3}{2})}\mathrm{nd}(\mathrm{ns})

states of barium, which lie ~5.6 eV above the first ionization limit of Ba, using two-photon excitation from the bound

6snd(\mathrm{ns})

Rydberg states. The two-photon excitation scheme requires rather modest laser power (~0.5 mJ), and the

{(6{d}_{\frac{5}{2}}n{d}_{j})}_{J=4}

states exhibit a sharp enhancement in the autoionization rate beyond

n=25

which is accompanied by the onset of ejection of very-low-energy electrons ( 0.02 eV). We observe that the

{6{d}_{\frac{5}{2}}n{d}_{j})}_{J=4}(n25)

states predominantly autoionize to the nearly degenerate

6{d}_{(\frac{3}{2})}

state of

{\mathrm{Ba}}^{+}

. This result has important implications for the development of autoionization lasers and the phenomenon of dielectronic recombination.