Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Collisional transfer between the 6s′[12]0,1 and 6p[12]1 xenon levels

N. Sadeghi, J. Sabbagh

Published Dec 1, 1977• 56 citations
Publisher

Abstract

The destruction rates of the xenon $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0}$ metastable and $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{1}$ resonance atoms by collisions with ground-state xenon atoms have been measured by studying the temporal dependence of the number densities of the $6{s}^{\ensuremath{'}}$ and $6p$ atoms. The studies have been made both during the earlier afterglow of a xenon pulsed discharge and after the selective production of the $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1}$ atoms by a laser excitation in the late afterglow. An original optical pumping technique, using a tunable pulsed dye laser, was employed to populate the $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1}$ levels by excitation of the $6s{[\frac{3}{2}]}_{2}$ long-lived metastable atoms to $6{p}^{\ensuremath{'}}$ levels. The pressure dependence of the decay frequencies of these $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1}$ atoms was analyzed in the xenon pressure range of 0.04 to 1 torr and a kinetic model describing the evolution of the densities of these atoms after their production was established. The rate coefficients for the relaxation of the $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0}$ metastable and $6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{1}$ resonance atoms by two-body collisions involving a ground-state xenon atom are (8.45\ifmmode\pm\else\textpm\fi{}0.85) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}12}$ ${\mathrm{cm}}^{3}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ and (6.65 \ifmmode\pm\else\textpm\fi{} 1.00) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}11}$ ${\mathrm{cm}}^{3}$ ${\mathrm{sec}}^{\ensuremath{-}1}$, respectively. Results show that, in fact, at least 75% of this relaxation is a transfer of population to the $6p{[\frac{1}{2}]}_{1}$ level following ${\mathrm{Xe}}^{*}(6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1})+\mathrm{Xe}\ensuremath{\rightleftarrows}{\mathrm{Xe}}^{*}(6p{[\frac{1}{2}]}_{1})+\mathrm{Xe}\ensuremath{-}\ensuremath{\Delta}E$. These collisional transfer processes have been explained by means of Mulliken's xenon molecular potential curves.

DOI
10.1103/physreva.16.2336

Related papers

Collisional effects on xenon 6p fluorescence

M. Rankin, Jon P. Davis, Christopher Giranda +1 more

We describe collision studies on the two-photon excitation and fluorescence of the xenon 6p[1/2,0] excited state. Molecular nitrogen is the major collision partner. The 250-nm second harmonic of a line-narrowed Hansch-type dye laser excites the 6p state of xenon by two-photon absorption. Sample mixtures contain xenon at a partial pressure of 1 Torr and nitrogen at partial pressures of up to several hundred Torr. Time-resolved and time-integrated measurements of the intensity of the 828-nm 6p[1/2,0]—6s[3/2,1] allowed transition are obtained with photomultipliers, a transient digitizer, and a computerized data acquisition system. We extract pressure-dependent and pressure-independent components of the fluorescence lifetime and fluorescence yield from measurements over a range of nitrogen pressures. When the excitation power density is of the order of 104 W/cm2, the excited xenon atoms decay spontaneously. For spontaneous fluorescence, we obtain an inelastic (quenching) collision cross section of ~10–14 cm2 for xenon-nitrogen collisions, and a pressure-broadening coefficient of ~3 × 107 Hz/(Torr N2) for the two-photon transition rate. For excitation intensities above 2.6 × 106 W/cm2, the xenon atoms radiate cooperatively in a subnanosecond pulse. The fluorescence yield of this cooperative emission increases with nitrogen pressure rather than decreasing as in the spontaneous case. Mechanisms are discussed.

Annual Meeting Optical Society of America•Jan 1, 1986•0 citations

Excitation transfer among, and quenching of, the barium 6s5d 3 DJ metastable levels due to collisions with argon, nitrogen, and barium perturbers

E. Ehrlacher, John Huennekens

We describe a set of experiments that investigate excitation transfer among the barium 6s5d $^{3}$${\mathit{D}}_{\mathit{J}}$ metastable levels due to collisions with argon perturber atoms, and quenching of atoms in these levels by nitrogen perturber molecules. The metastable levels were populated through optical pumping of the 6${\mathit{s}}^{2}$ $^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}6s6p $^{3}$${\mathit{P}}_{1}^{\mathit{o}}$ intercombination transition with a pulsed laser, followed by stimulated emission or stimulated Raman scattering into the 6s5d $^{3}$${\mathit{D}}_{1,2}$ levels. Collisional mixing then distributed population throughout the $^{3}$${\mathit{D}}_{\mathit{J}}$ levels. Time-dependent absorption coefficients were obtained by measuring the transmission of a weak cw probe laser beam (after the pulsed laser fired) at several perturber number densities. Argon buffer gas was used to investigate fine-structure mixing, and nitrogen was used to study quenching. The time-dependent absorption coefficients were fitted to appropriate fitting functions, obtained by solving the set of coupled rate equations used to model the time evolution of the metastable level populations. The buildup rates of the initially unpopulated $^{3}$${\mathit{D}}_{3}$ and underpopulated $^{3}$${\mathit{D}}_{1}$ levels were used to determine the collisional mixing rates, while the measured decay rates of the $^{3}$${\mathit{D}}_{\mathit{J}}$ level populations yielded the quenching rates. From plots of buildup rates versus argon number density for the $^{3}$${\mathit{D}}_{1,3}$ states, we were able to determine four of the six fine-structure mixing rate coefficients ${\mathit{k}}_{\mathit{i}\mathit{j}}$.The results are ${\mathit{k}}_{12}$=(1.71\ifmmode\pm\else\textpm\fi{}0.18), ${\mathit{k}}_{21}$=(1.39\ifmmode\pm\else\textpm\fi{}0.13), ${\mathit{k}}_{23}$=(1.42\ifmmode\pm\else\textpm\fi{}0.13), and ${\mathit{k}}_{32}$=(1.92\ifmmode\pm\else\textpm\fi{}0.16)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}13}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. The experiment is not sensitive to the values of ${\mathit{k}}_{13}$ and ${\mathit{k}}_{31}$. Estimated rate coefficients for excitation transfer among the $^{3}$${\mathit{D}}_{\mathit{J}}$ levels due to collisions with barium atoms are ${\mathit{k}}_{21}^{\mathrm{Ba}}$=1.3\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ and ${\mathit{k}}_{23}^{\mathrm{Ba}}$=5.8\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. A plot of the population decay rates versus ${\mathrm{N}}_{2}$ number density for each of the three metastable levels yielded the average nitrogen quenching rate coefficient ${\mathit{k}}_{\mathit{q}}$=(3.14\ifmmode\pm\else\textpm\fi{}0.19)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}11}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$.

Physical Review A•Dec 1, 1994•26 citations

Collisional relaxation of the 6s[3/2 ]10 and 6s’[1/2 ]10 mJ levels of xenon using resonantly enhanced multiphoton ionization

Dimitrios Charalambidis, A. Lyras, P. Lambropoulos +3 more

Collisional relaxation of the 6s${[3/2]}_{1}^{0}$ and 6s'${[1/2]}_{1}^{0}$ ${m}_{J}$ levels of Xe has been investigated both experimentally and theoretically. Collisional disalignment and dephasing of the ${m}_{J}$ levels have been studied by measuring the pressure and laser intensity dependence of the ratio of the ionization from selectively excited ${m}_{J}$=0 and \ifmmode\pm\else\textpm\fi{}1 sublevels in a three-photon resonant-ionization experiment via the 6s and 6s' states of Xe. The selective ionization is achieved by a novel use of two counterpropagating laser beams having parallel and orthogonal polarization, respectively. The pressure dependence of the ionization ratio has been calculated by solving a system of rate equations derived from a full set of density-matrix equations pertaining to the particular experimental conditions. Collisional-relaxation cross sections of the investigated levels have been estimated by fitting the calculated results to the experimental data. The ionization ratio is found to be sensitive to both disalignment and dephasing of the ${m}_{J}$ levels.

Physical Review A•Feb 1, 1990•7 citations

Diffusion of barium atoms in the 6s5d 3 DJ metastable levels and the 6 s2 1 S0 ground state through noble-gas perturbers

R. K. Namiotka, E. Ehrlacher, J. Sagle +5 more

We describe a set of experiments that investigate diffusion of barium 6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$ metastable level and 6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$ ground-state atoms through the noble gases: He, Ne, Ar, Kr, and Xe. The barium metastable levels were populated through optical pumping of the 6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}6s6p${\mathrm{}}^{3}$${\mathit{P}}_{1}^{\mathit{o}}$ intercombination transition with a pulsed laser, followed by spontaneous or stimulated emission into the 6s5d${\mathrm{}}^{3}$${\mathit{D}}_{1,2}$ levels. Collisional mixing then distributed population throughout the 6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$ levels. A weak narrow-band cw laser was tuned to appropriate transitions to probe the spatial distribution of metastable level atoms, as well as the hole created in the ground-state spatial distribution, by the pulsed laser. Time-dependent absorption coefficients were obtained by measuring the transmission of the probe laser at several different pump-probe spatial separations. From these absorption data, spatial number density profiles were mapped out for various times following the firing of the pump laser. These density profiles were used to determine the diffusion coefficient for each state at a particular buffer-gas pressure and temperature. From these pressure- and temperature-dependent diffusion coefficients D, we determined the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$) for the metastable and ground-state atoms diffusing through the noble gases, respectively. We also report values for the scaled standard diffusion coefficients ${\mathit{D}}_{0}$. Our experimental values of the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d${\mathrm{}}^{3}$${\mathit{D}}_{\mathit{J}}$) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$) for the barium-helium system are compared with values calculated from published, theoretical barium-helium potentials and the agreement is excellent. \textcopyright{} 1996 The American Physical Society.

Physical Review A•Jul 1, 1996•16 citations

Metastability-exchange and depolarising collisions in xenon and krypton

V. Lefèvre-Seguin, Michèle Leduc

Collisions between rare-gas atoms in the 3 P 2 metastable state and in the ground state were studied. The metastable atoms were created by a discharge and oriented by optical pumping, and pressure broadening of their magnetic-resonance curves was measured. For xenon, mixtures of even and odd isotopes were used, leading to a determination of the cross section for metastability-exchange collisions. For krypton the results are reported for the disorientation of the metastable state in the natural gas. In addition the disorientation cross section has been measured of the krypton metastable state through collisions with helium.

Journal of Physics B Atomic and Molecular Physics•Aug 1, 1977•13 citations

Magneto-optical trapping of metastable xenon: Isotope-shift measurements

M. Walhout, Henry J. L. Megens, A. Witte +1 more

We have magneto-optically trapped the nine stable isotopes of xenon. Using the Zeeman slowing method to decelerate a beam of xenon atoms in the metastable 6s 3/2 [3/2${]}_{2}$ state (notation representing nl ${\mathit{J}}_{\mathrm{core}}$ [K=${\mathit{J}}_{\mathrm{core}}$+l${]}_{\mathit{J}}$), we load our trap to a collisionally limited density of more than ${10}^{10}$ atoms/${\mathrm{cm}}^{3}$. The two odd isotopes are trapped without a repumping frequency, even though they have hyperfine structure. The sensitivity of the trapping process to the laser frequency is exploited to make accurate measurements of the isotope shifts for the 6s 3/2 [3/2${]}_{2}$\ensuremath{\rightarrow}6p 3/2 [5/2${]}_{3}$ laser-cooling transition and of the hyperfine constants for $^{131}\mathrm{Xe}$.

Physical Review A•Aug 1, 1993•70 citations
The destruction rates of the xenon 6s\ensuremath′[12]06{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0}6s\ensuremath′[21​]0​ metastable and 6s\ensuremath′[12]16{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{1}6s\ensuremath′[21​]1​ resonance atoms by collisions with ground-state xenon atoms have been measured by studying the temporal dependence of the number densities of the 6s\ensuremath′6{s}^{\ensuremath{'}}6s\ensuremath′ and 6p6p6p atoms. The studies have been made both during the earlier afterglow of a xenon pulsed discharge and after the selective production of the 6s\ensuremath′[12]0,16{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1}6s\ensuremath′[21​]0,1​ atoms by a laser excitation in the late afterglow. An original optical pumping technique, using a tunable pulsed dye laser, was employed to populate the 6s\ensuremath′[12]0,16{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1}6s\ensuremath′[21​]0,1​ levels by excitation of the 6s[32]26s{[\frac{3}{2}]}_{2}6s[23​]2​ long-lived metastable atoms to 6p\ensuremath′6{p}^{\ensuremath{'}}6p\ensuremath′ levels. The pressure dependence of the decay frequencies of these 6s\ensuremath′[12]0,16{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1}6s\ensuremath′[21​]0,1​ atoms was analyzed in the xenon pressure range of 0.04 to 1 torr and a kinetic model describing the evolution of the densities of these atoms after their production was established. The rate coefficients for the relaxation of the 6s\ensuremath′[12]06{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0}6s\ensuremath′[21​]0​ metastable and 6s\ensuremath′[12]16{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{1}6s\ensuremath′[21​]1​ resonance atoms by two-body collisions involving a ground-state xenon atom are (8.45\ifmmode\pm\else\textpm\fi{}0.85) \ifmmode\times\else\texttimes\fi{} 10\ensuremath−12{10}^{\ensuremath{-}12}10\ensuremath−12 cm3{\mathrm{cm}}^{3}cm3 sec\ensuremath−1{\mathrm{sec}}^{\ensuremath{-}1}sec\ensuremath−1 and (6.65 \ifmmode\pm\else\textpm\fi{} 1.00) \ifmmode\times\else\texttimes\fi{} 10\ensuremath−11{10}^{\ensuremath{-}11}10\ensuremath−11 cm3{\mathrm{cm}}^{3}cm3 sec\ensuremath−1{\mathrm{sec}}^{\ensuremath{-}1}sec\ensuremath−1, respectively. Results show that, in fact, at least 75% of this relaxation is a transfer of population to the 6p[12]16p{[\frac{1}{2}]}_{1}6p[21​]1​ level following Xe∗(6s\ensuremath′[12]0,1)+Xe\ensuremath⇄Xe∗(6p[12]1)+Xe\ensuremath−\ensuremathΔE{\mathrm{Xe}}^{*}(6{s}^{\ensuremath{'}}{[\frac{1}{2}]}_{0,1})+\mathrm{Xe}\ensuremath{\rightleftarrows}{\mathrm{Xe}}^{*}(6p{[\frac{1}{2}]}_{1})+\mathrm{Xe}\ensuremath{-}\ensuremath{\Delta}EXe∗(6s\ensuremath′[21​]0,1​)+Xe\ensuremath⇄Xe∗(6p[21​]1​)+Xe\ensuremath−\ensuremathΔE. These collisional transfer processes have been explained by means of Mulliken's xenon molecular potential curves.
We describe collision studies on the two-photon excitation and fluorescence of the xenon 6p[1/2,0] excited state. Molecular nitrogen is the major collision partner. The 250-nm second harmonic of a line-narrowed Hansch-type dye laser excites the 6p state of xenon by two-photon absorption. Sample mixtures contain xenon at a partial pressure of 1 Torr and nitrogen at partial pressures of up to several hundred Torr. Time-resolved and time-integrated measurements of the intensity of the 828-nm 6p[1/2,0]—6s[3/2,1] allowed transition are obtained with photomultipliers, a transient digitizer, and a computerized data acquisition system. We extract pressure-dependent and pressure-independent components of the fluorescence lifetime and fluorescence yield from measurements over a range of nitrogen pressures. When the excitation power density is of the order of 104 W/cm2, the excited xenon atoms decay spontaneously. For spontaneous fluorescence, we obtain an inelastic (quenching) collision cross section of ~10–14 cm2 for xenon-nitrogen collisions, and a pressure-broadening coefficient of ~3 × 107 Hz/(Torr N2) for the two-photon transition rate. For excitation intensities above 2.6 × 106 W/cm2, the xenon atoms radiate cooperatively in a subnanosecond pulse. The fluorescence yield of this cooperative emission increases with nitrogen pressure rather than decreasing as in the spontaneous case. Mechanisms are discussed.
We describe a set of experiments that investigate excitation transfer among the barium 6s5d 3^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​ metastable levels due to collisions with argon perturber atoms, and quenching of atoms in these levels by nitrogen perturber molecules. The metastable levels were populated through optical pumping of the 6s2{\mathit{s}}^{2}s2 1^{1}1S0{\mathit{S}}_{0}S0​\ensuremath{\rightarrow}6s6p 3^{3}3P1o{\mathit{P}}_{1}^{\mathit{o}}P1o​ intercombination transition with a pulsed laser, followed by stimulated emission or stimulated Raman scattering into the 6s5d 3^{3}3D1,2{\mathit{D}}_{1,2}D1,2​ levels. Collisional mixing then distributed population throughout the 3^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​ levels. Time-dependent absorption coefficients were obtained by measuring the transmission of a weak cw probe laser beam (after the pulsed laser fired) at several perturber number densities. Argon buffer gas was used to investigate fine-structure mixing, and nitrogen was used to study quenching. The time-dependent absorption coefficients were fitted to appropriate fitting functions, obtained by solving the set of coupled rate equations used to model the time evolution of the metastable level populations. The buildup rates of the initially unpopulated 3^{3}3D3{\mathit{D}}_{3}D3​ and underpopulated 3^{3}3D1{\mathit{D}}_{1}D1​ levels were used to determine the collisional mixing rates, while the measured decay rates of the 3^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​ level populations yielded the quenching rates. From plots of buildup rates versus argon number density for the 3^{3}3D1,3{\mathit{D}}_{1,3}D1,3​ states, we were able to determine four of the six fine-structure mixing rate coefficients kij{\mathit{k}}_{\mathit{i}\mathit{j}}kij​.The results are k12{\mathit{k}}_{12}k12​=(1.71\ifmmode\pm\else\textpm\fi{}0.18), k21{\mathit{k}}_{21}k21​=(1.39\ifmmode\pm\else\textpm\fi{}0.13), k23{\mathit{k}}_{23}k23​=(1.42\ifmmode\pm\else\textpm\fi{}0.13), and k32{\mathit{k}}_{32}k32​=(1.92\ifmmode\pm\else\textpm\fi{}0.16)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}13}$ cm3{\mathrm{cm}}^{3}cm3 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. The experiment is not sensitive to the values of k13{\mathit{k}}_{13}k13​ and k31{\mathit{k}}_{31}k31​. Estimated rate coefficients for excitation transfer among the 3^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​ levels due to collisions with barium atoms are k21Ba{\mathit{k}}_{21}^{\mathrm{Ba}}k21Ba​=1.3\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ cm3{\mathrm{cm}}^{3}cm3 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ and k23Ba{\mathit{k}}_{23}^{\mathrm{Ba}}k23Ba​=5.8\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ cm3{\mathrm{cm}}^{3}cm3 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. A plot of the population decay rates versus N2{\mathrm{N}}_{2}N2​ number density for each of the three metastable levels yielded the average nitrogen quenching rate coefficient kq{\mathit{k}}_{\mathit{q}}kq​=(3.14\ifmmode\pm\else\textpm\fi{}0.19)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}11}$ cm3{\mathrm{cm}}^{3}cm3 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$.
Collisional relaxation of the 6s[3/2]10{[3/2]}_{1}^{0}[3/2]10​ and 6s'[1/2]10{[1/2]}_{1}^{0}[1/2]10​ mJ{m}_{J}mJ​ levels of Xe has been investigated both experimentally and theoretically. Collisional disalignment and dephasing of the mJ{m}_{J}mJ​ levels have been studied by measuring the pressure and laser intensity dependence of the ratio of the ionization from selectively excited mJ{m}_{J}mJ​=0 and \ifmmode\pm\else\textpm\fi{}1 sublevels in a three-photon resonant-ionization experiment via the 6s and 6s' states of Xe. The selective ionization is achieved by a novel use of two counterpropagating laser beams having parallel and orthogonal polarization, respectively. The pressure dependence of the ionization ratio has been calculated by solving a system of rate equations derived from a full set of density-matrix equations pertaining to the particular experimental conditions. Collisional-relaxation cross sections of the investigated levels have been estimated by fitting the calculated results to the experimental data. The ionization ratio is found to be sensitive to both disalignment and dephasing of the mJ{m}_{J}mJ​ levels.
We describe a set of experiments that investigate diffusion of barium 6s5d3{\mathrm{}}^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​ metastable level and 6s2{\mathit{s}}^{2}s21{\mathrm{}}^{1}1S0{\mathit{S}}_{0}S0​ ground-state atoms through the noble gases: He, Ne, Ar, Kr, and Xe. The barium metastable levels were populated through optical pumping of the 6s2{\mathit{s}}^{2}s21{\mathrm{}}^{1}1S0{\mathit{S}}_{0}S0​\ensuremath{\rightarrow}6s6p3{\mathrm{}}^{3}3P1o{\mathit{P}}_{1}^{\mathit{o}}P1o​ intercombination transition with a pulsed laser, followed by spontaneous or stimulated emission into the 6s5d3{\mathrm{}}^{3}3D1,2{\mathit{D}}_{1,2}D1,2​ levels. Collisional mixing then distributed population throughout the 6s5d3{\mathrm{}}^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​ levels. A weak narrow-band cw laser was tuned to appropriate transitions to probe the spatial distribution of metastable level atoms, as well as the hole created in the ground-state spatial distribution, by the pulsed laser. Time-dependent absorption coefficients were obtained by measuring the transmission of the probe laser at several different pump-probe spatial separations. From these absorption data, spatial number density profiles were mapped out for various times following the firing of the pump laser. These density profiles were used to determine the diffusion coefficient for each state at a particular buffer-gas pressure and temperature. From these pressure- and temperature-dependent diffusion coefficients D, we determined the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d3{\mathrm{}}^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s2{\mathit{s}}^{2}s21{\mathrm{}}^{1}1S0{\mathit{S}}_{0}S0​) for the metastable and ground-state atoms diffusing through the noble gases, respectively. We also report values for the scaled standard diffusion coefficients D0{\mathit{D}}_{0}D0​. Our experimental values of the thermally averaged diffusion cross sections ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s5d3{\mathrm{}}^{3}3DJ{\mathit{D}}_{\mathit{J}}DJ​) and ${\mathrm{\ensuremath{\sigma}}}_{\mathit{D}}$(6s2{\mathit{s}}^{2}s21{\mathrm{}}^{1}1S0{\mathit{S}}_{0}S0​) for the barium-helium system are compared with values calculated from published, theoretical barium-helium potentials and the agreement is excellent. \textcopyright{} 1996 The American Physical Society.
Collisions between rare-gas atoms in the 3 P 2 metastable state and in the ground state were studied. The metastable atoms were created by a discharge and oriented by optical pumping, and pressure broadening of their magnetic-resonance curves was measured. For xenon, mixtures of even and odd isotopes were used, leading to a determination of the cross section for metastability-exchange collisions. For krypton the results are reported for the disorientation of the metastable state in the natural gas. In addition the disorientation cross section has been measured of the krypton metastable state through collisions with helium.
We have magneto-optically trapped the nine stable isotopes of xenon. Using the Zeeman slowing method to decelerate a beam of xenon atoms in the metastable 6s 3/2 [3/2]2{]}_{2}]2​ state (notation representing nl Jcore{\mathit{J}}_{\mathrm{core}}Jcore​ [K=Jcore{\mathit{J}}_{\mathrm{core}}Jcore​+l]J{]}_{\mathit{J}}]J​), we load our trap to a collisionally limited density of more than 1010{10}^{10}1010 atoms/cm3{\mathrm{cm}}^{3}cm3. The two odd isotopes are trapped without a repumping frequency, even though they have hyperfine structure. The sensitivity of the trapping process to the laser frequency is exploited to make accurate measurements of the isotope shifts for the 6s 3/2 [3/2]2{]}_{2}]2​\ensuremath{\rightarrow}6p 3/2 [5/2]3{]}_{3}]3​ laser-cooling transition and of the hyperfine constants for 131Xe^{131}\mathrm{Xe}131Xe.