Physical Review A

Photoionization-cross-section measurement of the Rb85 5 P3/22 excited state using microwave cavity resonance spectroscopy

M. A. W. van Ninhuijs, Job Beckers, O.J. Luiten

Published Dec 23, 2022• 0 citations

Abstract

We present microwave cavity resonance spectroscopy as a technique to determine excited-state photoionization cross sections of laser-cooled atoms. We demonstrate this technique by measuring the photoionization cross section of the $5^{2}P_{3/2}({F}^{\ensuremath{'}}=4)$ excited state of $^{85}\mathrm{Rb}$ to continuum by creating an ultracold plasma inside a 5-GHz resonant microwave cavity. We find a photoionization cross section of $\ensuremath{\sim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}22}\phantom{\rule{4pt}{0ex}}{\mathrm{m}}^{2}$ for photon excess energies of 50, 100, 200, and 500 K above the ionization threshold. The measurements yield a cross section which is approximately 2 to 3 times smaller than the value provided by existing theory for the $5p$ excited state of $^{85}\mathrm{Rb}$ and two earlier measurements performed with other techniques for similar excess energies.

DOI: 10.1103/physreva.106.063110

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Photoionization and cold collision studies using trapped atoms

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Photoionization from the 5p 2P3/2 state of rubidium

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Physical Review AJun 8, 201120 citations

Photoionization cross sections of the 5S1/2 and 5P3/2 states of Rb in simultaneous magneto-optical trapping of Rb and Hg

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Physical Review A

Photoionization-cross-section measurement of the Rb85 5 P3/22 excited state using microwave cavity resonance spectroscopy

M. A. W. van Ninhuijs, Job Beckers, O.J. Luiten

Published Dec 23, 2022• 0 citations

Publisher

Abstract

5^{2}P_{3/2}({F}^{\ensuremath{'}}=4)

excited state of

^{85}\mathrm{Rb}

to continuum by creating an ultracold plasma inside a 5-GHz resonant microwave cavity. We find a photoionization cross section of

\ensuremath{\sim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}22}\phantom{\rule{4pt}{0ex}}{\mathrm{m}}^{2}

for photon excess energies of 50, 100, 200, and 500 K above the ionization threshold. The measurements yield a cross section which is approximately 2 to 3 times smaller than the value provided by existing theory for the

5p

excited state of

^{85}\mathrm{Rb}

and two earlier measurements performed with other techniques for similar excess energies.

DOI: 10.1103/physreva.106.063110

Related papers

Photoionization and cold collision studies using trapped atoms

P. L. Gould

The authors have used laser cooling and trapping techniques to investigate photoionization and cold collisions. With laser-trapped Rb, they have measured the photoionization cross section from the first excited (5P) level by observing the photoionization-induced loss rate of neutral atoms from the trap. This technique has the advantage that it directly measures the photoionization rate per atom. Knowing the ionizing laser intensity and the excited-state fraction, the measured loss rate gives the absolute cross section. Using this technique, the Rb 5P photoionization cross section at {approximately}400 nm has been determined with an uncertainty of 9%. The authors are currently attempting to extend this method to the 5D level. Using time-ordered pulses of diode-laser light (similar to the STIRAP technique), they have performed very efficient two-photon excitation of trapped Rb atoms to 5D. Finally, they will present results from a recent collaboration which combines measurements form conventional molecular spectroscopy (single photon and double resonance) with photoassociation collisions of ultracold Na atoms to yield a precise ({le}1 ppm) value for the dissociation energy of the X {Sigma}{sub g}{sub +} ground state of the Na{sub 2} molecule.The authors have used laser cooling and trapping techniques to investigate photoionization and cold collisions. With laser-trapped Rb, they have measured the photoionization cross section from the first excited (5P) level by observing the photoionization-induced loss rate of neutral atoms from the trap. This technique has the advantage that it directly measures the photoionization rate per atom. Knowing the ionizing laser intensity and the excited-state fraction, the measured loss rate gives the absolute cross section. Using this technique, the Rb 5P photoionization cross section at {approximately}400 nm has been determined with an uncertainty of 9%. The authors are currently attempting to extend this method to the 5D level. Using time-ordered pulses of diode-laser light (similar to the STIRAP technique), they have performed very efficient two-photon excitation of trapped Rb atoms to 5D. Finally, they will present results from a recent collaboration which combines measurements form conventional molecular spectroscopy (single photon and double resonance) with photoassociation collisions of ultracold Na atoms to yield a precise ({le}1 ppm) value for the dissociation energy of the X {Sigma}{sub g}{sub +} ground state of the Na{sub 2} molecule.

Bulletin of the American Physical SocietyMay 1, 19960 citations

Photoionization from the 5p 2P3/2 state of rubidium

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We report two-step photoionization studies from the 5 $p$ ${}^{2}$ ${P}_{3/2}$ excited state of rubidium using two dye lasers simultaneously pumped by a common Nd:YAG laser in conjunction with a thermionic diode ion detector. The photoionization cross section at the first ionization threshold is measured as 18.8 \ifmmode\pm\else\textpm\fi{} 3 Mb and at excess energies of 0.013, 0.106, 0.229, and 0.329 eV is measured as 15, 13.6, 12.6, and 12.5 Mb, respectively. The measured value of the photoionization cross section at the threshold is used to calibrate the oscillator strengths of the 5 $p$ ${}^{2}$ ${P}_{3/2}$ \ensuremath{\rightarrow} $n$ d ${}^{2}$ ${D}_{5/2}$ (22 \ensuremath{\leqslant} $n$ \ensuremath{\leqslant} 52) Rydberg transitions.We report two-step photoionization studies from the 5$p$ ${}^{2}$${P}_{3/2}$ excited state of rubidium using two dye lasers simultaneously pumped by a common Nd:YAG laser in conjunction with a thermionic diode ion detector. The photoionization cross section at the first ionization threshold is measured as 18.8 \ifmmode\pm\else\textpm\fi{} 3 Mb and at excess energies of 0.013, 0.106, 0.229, and 0.329 eV is measured as 15, 13.6, 12.6, and 12.5 Mb, respectively. The measured value of the photoionization cross section at the threshold is used to calibrate the oscillator strengths of the 5$p$ ${}^{2}$${P}_{3/2}$ \ensuremath{\rightarrow} $n$d ${}^{2}$${D}_{5/2}$ (22 \ensuremath{\leqslant} $n$ \ensuremath{\leqslant} 52) Rydberg transitions.

Physical Review AJun 8, 201120 citations

Photoionization cross sections of the 5S1/2 and 5P3/2 states of Rb in simultaneous magneto-optical trapping of Rb and Hg

M. Witkowski, Rodolfo Munoz-Rodriguez, Andrzej Raczyński +5 more

We report the measurement of the photoionization cross sections of the $5{S}_{1/2}$ and $5{P}_{3/2}$ states of $^{87}\mathrm{Rb}$ in a two-species Hg and Rb magneto-optical trap (MOT) by the cooling laser for Hg. The photoionization cross sections of Rb in the $5{S}_{1/2}$ and $5{P}_{3/2}$ states at 253.7 nm are determined to be ${1}_{\ensuremath{-}1}^{+4.3}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$ and $4.63(30)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}18}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$, respectively. To measure the $5{S}_{1/2}$ and $5{P}_{3/2}$ state fractions in the MOT we detected the photoionization rate of the $5{P}_{3/2}$ state by an additional 401.5 nm laser. The photoionization cross section of Rb in the $5{P}_{3/2}$ state at 401.5 nm is determined to be $\text{1.18(10)}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$.We report the measurement of the photoionization cross sections of the $5{S}_{1/2}$ and $5{P}_{3/2}$ states of $^{87}\mathrm{Rb}$ in a two-species Hg and Rb magneto-optical trap (MOT) by the cooling laser for Hg. The photoionization cross sections of Rb in the $5{S}_{1/2}$ and $5{P}_{3/2}$ states at 253.7 nm are determined to be ${1}_{\ensuremath{-}1}^{+4.3}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$ and $4.63(30)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}18}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$, respectively. To measure the $5{S}_{1/2}$ and $5{P}_{3/2}$ state fractions in the MOT we detected the photoionization rate of the $5{P}_{3/2}$ state by an additional 401.5 nm laser. The photoionization cross section of Rb in the $5{P}_{3/2}$ state at 401.5 nm is determined to be $\text{1.18(10)}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$.

arXiv:1810.12211Physical Review ANov 29, 201810 citations

Photoionization cross sections for excited laser-cooled cesium atoms

Onofrio M. Maragò, D. Ciampini, F. Fuso +3 more

Losses from a cesium magneto-optical trap induced by an additional laser ionizing the atoms in the ${6P}_{3/2}$ state have been measured as a function of the intensity and frequency of the ionizing laser. The absolute cross section for ionization of the ${6P}_{3/2}$ state has been derived as a function of the wavelength of the ionizing laser. Our values are compared with previous ones and available theoretical predictions. A simple model describing the photoionization processes has been developed.Losses from a cesium magneto-optical trap induced by an additional laser ionizing the atoms in the ${6P}_{3/2}$ state have been measured as a function of the intensity and frequency of the ionizing laser. The absolute cross section for ionization of the ${6P}_{3/2}$ state has been derived as a function of the wavelength of the ionizing laser. Our values are compared with previous ones and available theoretical predictions. A simple model describing the photoionization processes has been developed.

Physical Review AJun 1, 199837 citations

Measurement of the Absolute Photoionization Cross Section for the 5 P 3/2 State of 87 Rb in a Vapor Cell Magneto-optic Trap

Wei Huang, Ya-Ping Ruan, Feng-Dong Jia +6 more

We report the measurement of the absolute photoionization cross section for the 5P 3/2 state of 87 Rb at wavelength of 473 nm, which results in the photoelectron energies of 33 meV above the ionization threshold, using cold atoms confined in a vapor-loaded magneto-optical trap. The 87 Rb 5P 3/2 photoionization cross section at 473 nm is determined to be σ PI = 10.5 ± 2.2 Mb. Considering the spatial distribution of the trapped atoms, the average intensity of the ionization laser seen by an atom in the MOT instead of ionizing laser intensity I PI is used in our calculations for the photoionization cross sections. The excited state fraction is also accurately estimated using the latest experimental result.We report the measurement of the absolute photoionization cross section for the 5P 3/2 state of 87 Rb at wavelength of 473 nm, which results in the photoelectron energies of 33 meV above the ionization threshold, using cold atoms confined in a vapor-loaded magneto-optical trap. The 87 Rb 5P 3/2 photoionization cross section at 473 nm is determined to be σ PI = 10.5 ± 2.2 Mb. Considering the spatial distribution of the trapped atoms, the average intensity of the ionization laser seen by an atom in the MOT instead of ionizing laser intensity I PI is used in our calculations for the photoionization cross sections. The excited state fraction is also accurately estimated using the latest experimental result.

Chinese Physics LettersJan 1, 20128 citations

Photoionization Cross Section Measurement of Rb 5P3/2

Charles Young

Jan 1, 20120 citations

5^{2}P_{3/2}({F}^{\ensuremath{'}}=4)

excited state of

^{85}\mathrm{Rb}

to continuum by creating an ultracold plasma inside a 5-GHz resonant microwave cavity. We find a photoionization cross section of

\ensuremath{\sim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}22}\phantom{\rule{4pt}{0ex}}{\mathrm{m}}^{2}

5p

excited state of

^{85}\mathrm{Rb}

and two earlier measurements performed with other techniques for similar excess energies.

We report two-step photoionization studies from the 5

p

{}^{2}

{P}_{3/2}

excited state of rubidium using two dye lasers simultaneously pumped by a common Nd:YAG laser in conjunction with a thermionic diode ion detector. The photoionization cross section at the first ionization threshold is measured as 18.8 \ifmmode\pm\else\textpm\fi{} 3 Mb and at excess energies of 0.013, 0.106, 0.229, and 0.329 eV is measured as 15, 13.6, 12.6, and 12.5 Mb, respectively. The measured value of the photoionization cross section at the threshold is used to calibrate the oscillator strengths of the 5

p

{}^{2}

{P}_{3/2}

\ensuremath{\rightarrow}

n

{}^{2}

{D}_{5/2}

(22 \ensuremath{\leqslant}

n

\ensuremath{\leqslant} 52) Rydberg transitions.

We report the measurement of the photoionization cross sections of the

5{S}_{1/2}

and

5{P}_{3/2}

states of

^{87}\mathrm{Rb}

in a two-species Hg and Rb magneto-optical trap (MOT) by the cooling laser for Hg. The photoionization cross sections of Rb in the

5{S}_{1/2}

and

5{P}_{3/2}

states at 253.7 nm are determined to be ${1}_{\ensuremath{-}1}^{+4.3}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}20}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$ and $4.63(30)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}18}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$, respectively. To measure the

5{S}_{1/2}

and

5{P}_{3/2}

state fractions in the MOT we detected the photoionization rate of the

5{P}_{3/2}

state by an additional 401.5 nm laser. The photoionization cross section of Rb in the

5{P}_{3/2}

state at 401.5 nm is determined to be $\text{1.18(10)}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}\phantom{\rule{0.28em}{0ex}}{\text{cm}}^{2}$.

Losses from a cesium magneto-optical trap induced by an additional laser ionizing the atoms in the

{6P}_{3/2}

state have been measured as a function of the intensity and frequency of the ionizing laser. The absolute cross section for ionization of the

{6P}_{3/2}

state has been derived as a function of the wavelength of the ionizing laser. Our values are compared with previous ones and available theoretical predictions. A simple model describing the photoionization processes has been developed.