Physical Review A

Determination of the branching of the P11 Ba i level from studies of the intensity dependence of resonance fluorescence

D. A. Lewis, Jitendra Kumar, M. A. Finn, G. W. Greenlees

Published Jan 1, 1987• 19 citations

Abstract

The resonance fluorescence from the $^{138}\mathrm{Ba}$ I 5535-\AA{} 6${\mathit{s}}^{21}$${\mathit{S}}_{0}$-6s6p $^{1}$${\mathit{P}}_{1}$ transition has been measured as a function of incident intensity using a Doppler-free atomic beam geometry and a single-mode cw dye laser. The upper $^{1}\mathrm{P}_{1}$ level has a weak branch to intermediate metastable D states. A long laser-atom interaction region was used, which ensured that essentially all atoms could be pumped into the D states during their transit through the laser beam. By analyzing the shape of the saturation curve a value for the branching ratio to the 6s5d $^{1}$,3D levels of (3.57\ifmmode\pm\else\textpm\fi{}0.38)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}3}$ has been obtained.

DOI: 10.1103/physreva.35.131

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Optical pumping to the6s5dstates in atomic barium

Edmund G. Myers, C. Bell, P. G. Pappas +1 more

Physical Review AApr 1, 198615 citations

Stark-shift measurement of the (6s )2 1 S0 →(6s6p )1 P1 barium transition

Junlei Li, William Arie van Wijngaarden

Physical Review AMay 1, 199511 citations

Isotope-selective photoionization spectroscopy of barium

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Oscillator strength measurements of the 5s6s S10→5snp P11 Rydberg transitions of strontium

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Physical Review AApr 3, 200911 citations

Physical Review A

Determination of the branching of the P11 Ba i level from studies of the intensity dependence of resonance fluorescence

D. A. Lewis, Jitendra Kumar, M. A. Finn, G. W. Greenlees

Published Jan 1, 1987• 19 citations

Publisher

Abstract

The resonance fluorescence from the

^{138}\mathrm{Ba}

I 5535-\AA{} 6

{\mathit{s}}^{21}$${\mathit{S}}_{0}

-6s6p

^{1}$${\mathit{P}}_{1}

transition has been measured as a function of incident intensity using a Doppler-free atomic beam geometry and a single-mode cw dye laser. The upper

^{1}\mathrm{P}_{1}

level has a weak branch to intermediate metastable D states. A long laser-atom interaction region was used, which ensured that essentially all atoms could be pumped into the D states during their transit through the laser beam. By analyzing the shape of the saturation curve a value for the branching ratio to the 6s5d

^{1}

,3D levels of (3.57\ifmmode\pm\else\textpm\fi{}0.38)\ifmmode\times\else\texttimes\fi{}

{10}^{\mathrm{\ensuremath{-}}3}

has been obtained.

DOI: 10.1103/physreva.35.131

Related papers

Optical pumping to the6s5dstates in atomic barium

Edmund G. Myers, C. Bell, P. G. Pappas +1 more

Using a flow apparatus, the time dependence of 6 ${s}^{2}$ ${\mathrm{}}^{1}$ ${S}_{0}$ --6s6p ${\mathrm{}}^{1}$ ${P}_{1}$ (553.5 nm) resonance fluorescence in atomic barium has been studied following switch-on of cw laser excitation. It was found that the fluorescence decays with rates as great as 1.3\ifmmode\times\else\texttimes\fi{} ${10}^{6}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. Assuming this can be ascribed to the pumping of atoms to the 6s5d ${\mathrm{}}^{1}$ D and $^{3}\mathrm{D}$ metastable levels, a value for the sum of the transition probabilities can be extracted.Using a flow apparatus, the time dependence of 6${s}^{2}$ ${\mathrm{}}^{1}$${S}_{0}$--6s6p ${\mathrm{}}^{1}$${P}_{1}$ (553.5 nm) resonance fluorescence in atomic barium has been studied following switch-on of cw laser excitation. It was found that the fluorescence decays with rates as great as 1.3\ifmmode\times\else\texttimes\fi{}${10}^{6}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. Assuming this can be ascribed to the pumping of atoms to the 6s5d ${\mathrm{}}^{1}$D and $^{3}\mathrm{D}$ metastable levels, a value for the sum of the transition probabilities can be extracted.

Physical Review AApr 1, 198615 citations

Stark-shift measurement of the (6s )2 1 S0 →(6s6p )1 P1 barium transition

Junlei Li, William Arie van Wijngaarden

The Stark shift of the (6s ${)}^{2}$ $^{1}$ ${\mathit{S}}_{0}$ \ensuremath{\rightarrow}(6s6p ${)}^{1}$ ${\mathit{P}}_{1}$ transition in barium was measured using a laser to excite an atomic beam as it traversed a uniform electric field and a field-free region. The laser frequency was scanned across the transition while fluorescence produced by the radiative decay of the excited state was detected. The frequency scan was calibrated using an acousto-optic modulator which frequency shifted the laser by a specified amount. The Stark-shift rate was found to be -28.532\ifmmode\pm\else\textpm\fi{}0.060 kHz/(kV/cm ${)}^{2}$ . The hyperfine splitting of the $^{135,137}\mathrm{Ba}$ F=1/2 level relative to $^{138}\mathrm{Ba}$ of the (6s6p ${)}^{1}$ ${\mathit{P}}_{1}$ state was determined to be -549.47\ifmmode\pm\else\textpm\fi{}0.12 MHz, where the minus sign indicates that the $^{138}\mathrm{Ba}$ transition is at a lower frequency.The Stark shift of the (6s${)}^{2}$ $^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}(6s6p${)}^{1}$${\mathit{P}}_{1}$ transition in barium was measured using a laser to excite an atomic beam as it traversed a uniform electric field and a field-free region. The laser frequency was scanned across the transition while fluorescence produced by the radiative decay of the excited state was detected. The frequency scan was calibrated using an acousto-optic modulator which frequency shifted the laser by a specified amount. The Stark-shift rate was found to be -28.532\ifmmode\pm\else\textpm\fi{}0.060 kHz/(kV/cm${)}^{2}$. The hyperfine splitting of the $^{135,137}\mathrm{Ba}$ F=1/2 level relative to $^{138}\mathrm{Ba}$ of the (6s6p${)}^{1}$${\mathit{P}}_{1}$ state was determined to be -549.47\ifmmode\pm\else\textpm\fi{}0.12 MHz, where the minus sign indicates that the $^{138}\mathrm{Ba}$ transition is at a lower frequency.

Physical Review AMay 1, 199511 citations

Isotope-selective photoionization spectroscopy of barium

Darrell J. Armstrong, J. Cooper

We demonstrate an experimental technique that selects the nuclear spin I=0 isotope $^{138}\mathrm{Ba}$ for spectroscopic measurements from a beam of natural barium containing seven stable isotopes. A cw dye laser is used to optically pump the I=3/2 isotopes $^{135}\mathrm{Ba}$ and $^{137}\mathrm{Ba}$ into the metastable 6s5d $^{1}$ ${\mathit{D}}_{2}$ and $^{3}$ ${\mathit{D}}_{1,2}$ levels via the 6s6p $^{1}$ ${\mathit{P}}_{1}$ excited state, leaving nearly pure $^{138}\mathrm{Ba}$ in the ground state. Photoionization spectra of the excited 5d6p $^{3}$ ${\mathit{D}}_{1}$ even isotope state recorded with optical pumping of $^{135}\mathrm{Ba}$ and $^{137}\mathrm{Ba}$ to the metastable levels are essentially devoid of forbidden features associated with the hyperfine interaction in the odd isotopes.We demonstrate an experimental technique that selects the nuclear spin I=0 isotope $^{138}\mathrm{Ba}$ for spectroscopic measurements from a beam of natural barium containing seven stable isotopes. A cw dye laser is used to optically pump the I=3/2 isotopes $^{135}\mathrm{Ba}$ and $^{137}\mathrm{Ba}$ into the metastable 6s5d $^{1}$${\mathit{D}}_{2}$ and $^{3}$${\mathit{D}}_{1,2}$ levels via the 6s6p $^{1}$${\mathit{P}}_{1}$ excited state, leaving nearly pure $^{138}\mathrm{Ba}$ in the ground state. Photoionization spectra of the excited 5d6p $^{3}$${\mathit{D}}_{1}$ even isotope state recorded with optical pumping of $^{135}\mathrm{Ba}$ and $^{137}\mathrm{Ba}$ to the metastable levels are essentially devoid of forbidden features associated with the hyperfine interaction in the odd isotopes.

Physical Review AApr 1, 199311 citations

Energy-pooling collisions in barium

Jonathan Andrew Neuman, Alan C. Gallagher, J. Cooper

Rate coefficients for energy-pooling collisions between low-lying excited states of Ba have been measured. The 6s6p ${(}^{3}$ ${\mathit{P}}_{1}$ ) level in Ba is pumped by a cw diode laser, and radiative decay and collisions with buffer-gas atoms also populate the 5d6s ${(}^{1}$ D) and 5d6s ${(}^{3}$ D) metastable levels. The densities of these low-lying excited states are measured by the absorption of lines from a Ba hollow-cathode lamp, and the states populated by energy-pooling collisions are studied by comparing their fluorescence intensity to that of the laser-excited level. The rate coefficients are on the order of gas-kinetic rates, and they are not strongly dependent on energy defect, spin changes, or angular-momentum changes.Rate coefficients for energy-pooling collisions between low-lying excited states of Ba have been measured. The 6s6p${(}^{3}$${\mathit{P}}_{1}$) level in Ba is pumped by a cw diode laser, and radiative decay and collisions with buffer-gas atoms also populate the 5d6s${(}^{1}$D) and 5d6s${(}^{3}$D) metastable levels. The densities of these low-lying excited states are measured by the absorption of lines from a Ba hollow-cathode lamp, and the states populated by energy-pooling collisions are studied by comparing their fluorescence intensity to that of the laser-excited level. The rate coefficients are on the order of gas-kinetic rates, and they are not strongly dependent on energy defect, spin changes, or angular-momentum changes.

Physical Review AAug 1, 199420 citations

High-Resolution Electron Spectroscopy of Laser-Excited Ba Rydberg Atoms

Herbert H. Rinneberg, Jörg Neukammer, U. Majewski +1 more

The ionization of $6sns^{1}S_{0}$ Rydberg states of $^{138}\mathrm{Ba}$ has been investigated by high-resolution electron spectroscopy. The Rydberg states were excited by two cw dye lasers via the $6s6p^{1}P_{1}$ level. The electron spectra show rich structure between 0.025 and 3 eV, largely attributable to collisional (Penning) ionization, photoionization, and autoionizing transitions. The first process might be interpreted as superelastic scattering of the Rydberg electron by optically pumped $\mathrm{Ba}(6s6p^{1}P_{1})$ or $\mathrm{Ba}(6s5d^{1}D_{2})$ atoms.The ionization of $6sns^{1}S_{0}$ Rydberg states of $^{138}\mathrm{Ba}$ has been investigated by high-resolution electron spectroscopy. The Rydberg states were excited by two cw dye lasers via the $6s6p^{1}P_{1}$ level. The electron spectra show rich structure between 0.025 and 3 eV, largely attributable to collisional (Penning) ionization, photoionization, and autoionizing transitions. The first process might be interpreted as superelastic scattering of the Rydberg electron by optically pumped $\mathrm{Ba}(6s6p^{1}P_{1})$ or $\mathrm{Ba}(6s5d^{1}D_{2})$ atoms.

Physical Review LettersOct 24, 198315 citations

Oscillator strength measurements of the 5s6s S10→5snp P11 Rydberg transitions of strontium

Sami Ul Haq, Mazhar Ali Kalyar, M. Rafiq +3 more

We report the experimentally determined oscillator strengths for the $5s6s$ ${^{1}S}_{0}\ensuremath{\rightarrow}5snp$ ${^{1}P}_{1}$ Rydberg transitions of strontium using two-step excitation in conjunction with a thermionic diode ion detector. The absolute photoionization cross section from the $5s6s$ ${^{1}S}_{0}$ excited state has been determined by adjusting the polarization vector of the ionizing laser beam parallel, perpendicular, and at the magic angle with respect to that of the exciting dye laser. The measured absolute value of the photoionization cross section $0.9\ifmmode\pm\else\textpm\fi{}0.2\text{ }\text{Mb}$ at the $5s$ threshold is used to extract the $f$ values of the $5s6s$ ${^{1}S}_{0}\ensuremath{\rightarrow}5snp$ ${^{1}P}_{1}$ $(26\ensuremath{\le}n\ensuremath{\le}73)$ Rydberg transitions. The oscillator strength in the discrete region merges smoothly to the oscillator strength density at the ionization threshold.We report the experimentally determined oscillator strengths for the $5s6s$ ${^{1}S}_{0}\ensuremath{\rightarrow}5snp$ ${^{1}P}_{1}$ Rydberg transitions of strontium using two-step excitation in conjunction with a thermionic diode ion detector. The absolute photoionization cross section from the $5s6s$ ${^{1}S}_{0}$ excited state has been determined by adjusting the polarization vector of the ionizing laser beam parallel, perpendicular, and at the magic angle with respect to that of the exciting dye laser. The measured absolute value of the photoionization cross section $0.9\ifmmode\pm\else\textpm\fi{}0.2\text{ }\text{Mb}$ at the $5s$ threshold is used to extract the $f$ values of the $5s6s$ ${^{1}S}_{0}\ensuremath{\rightarrow}5snp$ ${^{1}P}_{1}$ $(26\ensuremath{\le}n\ensuremath{\le}73)$ Rydberg transitions. The oscillator strength in the discrete region merges smoothly to the oscillator strength density at the ionization threshold.

Physical Review AApr 3, 200911 citations

The resonance fluorescence from the

^{138}\mathrm{Ba}

I 5535-\AA{} 6

{\mathit{s}}^{21}$${\mathit{S}}_{0}

-6s6p

^{1}$${\mathit{P}}_{1}

transition has been measured as a function of incident intensity using a Doppler-free atomic beam geometry and a single-mode cw dye laser. The upper

^{1}\mathrm{P}_{1}

^{1}

,3D levels of (3.57\ifmmode\pm\else\textpm\fi{}0.38)\ifmmode\times\else\texttimes\fi{}

{10}^{\mathrm{\ensuremath{-}}3}

has been obtained.

Using a flow apparatus, the time dependence of 6

{s}^{2}

{\mathrm{}}^{1}

{S}_{0}

--6s6p

{\mathrm{}}^{1}

{P}_{1}

(553.5 nm) resonance fluorescence in atomic barium has been studied following switch-on of cw laser excitation. It was found that the fluorescence decays with rates as great as 1.3\ifmmode\times\else\texttimes\fi{}

{10}^{6}

${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. Assuming this can be ascribed to the pumping of atoms to the 6s5d

{\mathrm{}}^{1}

D and

^{3}\mathrm{D}

metastable levels, a value for the sum of the transition probabilities can be extracted.

The Stark shift of the (6s

{)}^{2}

^{1}

{\mathit{S}}_{0}

\ensuremath{\rightarrow}(6s6p

{)}^{1}

{\mathit{P}}_{1}

transition in barium was measured using a laser to excite an atomic beam as it traversed a uniform electric field and a field-free region. The laser frequency was scanned across the transition while fluorescence produced by the radiative decay of the excited state was detected. The frequency scan was calibrated using an acousto-optic modulator which frequency shifted the laser by a specified amount. The Stark-shift rate was found to be -28.532\ifmmode\pm\else\textpm\fi{}0.060 kHz/(kV/cm

{)}^{2}

. The hyperfine splitting of the

^{135,137}\mathrm{Ba}

F=1/2 level relative to

^{138}\mathrm{Ba}

of the (6s6p

{)}^{1}

{\mathit{P}}_{1}

state was determined to be -549.47\ifmmode\pm\else\textpm\fi{}0.12 MHz, where the minus sign indicates that the

^{138}\mathrm{Ba}

transition is at a lower frequency.

We demonstrate an experimental technique that selects the nuclear spin I=0 isotope

^{138}\mathrm{Ba}

for spectroscopic measurements from a beam of natural barium containing seven stable isotopes. A cw dye laser is used to optically pump the I=3/2 isotopes

^{135}\mathrm{Ba}

and

^{137}\mathrm{Ba}

into the metastable 6s5d

^{1}

{\mathit{D}}_{2}

and

^{3}

{\mathit{D}}_{1,2}

levels via the 6s6p

^{1}

{\mathit{P}}_{1}

excited state, leaving nearly pure

^{138}\mathrm{Ba}

in the ground state. Photoionization spectra of the excited 5d6p

^{3}

{\mathit{D}}_{1}

even isotope state recorded with optical pumping of

^{135}\mathrm{Ba}

and

^{137}\mathrm{Ba}

to the metastable levels are essentially devoid of forbidden features associated with the hyperfine interaction in the odd isotopes.

Rate coefficients for energy-pooling collisions between low-lying excited states of Ba have been measured. The 6s6p

{(}^{3}

{\mathit{P}}_{1}

) level in Ba is pumped by a cw diode laser, and radiative decay and collisions with buffer-gas atoms also populate the 5d6s

{(}^{1}

D) and 5d6s

{(}^{3}

D) metastable levels. The densities of these low-lying excited states are measured by the absorption of lines from a Ba hollow-cathode lamp, and the states populated by energy-pooling collisions are studied by comparing their fluorescence intensity to that of the laser-excited level. The rate coefficients are on the order of gas-kinetic rates, and they are not strongly dependent on energy defect, spin changes, or angular-momentum changes.

The ionization of

6sns^{1}S_{0}

Rydberg states of

^{138}\mathrm{Ba}

has been investigated by high-resolution electron spectroscopy. The Rydberg states were excited by two cw dye lasers via the

6s6p^{1}P_{1}

level. The electron spectra show rich structure between 0.025 and 3 eV, largely attributable to collisional (Penning) ionization, photoionization, and autoionizing transitions. The first process might be interpreted as superelastic scattering of the Rydberg electron by optically pumped

\mathrm{Ba}(6s6p^{1}P_{1})

\mathrm{Ba}(6s5d^{1}D_{2})

atoms.

We report the experimentally determined oscillator strengths for the

5s6s

${^{1}S}_{0}\ensuremath{\rightarrow}5snp$

{^{1}P}_{1}

Rydberg transitions of strontium using two-step excitation in conjunction with a thermionic diode ion detector. The absolute photoionization cross section from the

5s6s

{^{1}S}_{0}

excited state has been determined by adjusting the polarization vector of the ionizing laser beam parallel, perpendicular, and at the magic angle with respect to that of the exciting dye laser. The measured absolute value of the photoionization cross section $0.9\ifmmode\pm\else\textpm\fi{}0.2\text{ }\text{Mb}$ at the

5s

threshold is used to extract the

f

values of the

5s6s

${^{1}S}_{0}\ensuremath{\rightarrow}5snp$

{^{1}P}_{1}

$(26\ensuremath{\le}n\ensuremath{\le}73)$ Rydberg transitions. The oscillator strength in the discrete region merges smoothly to the oscillator strength density at the ionization threshold.