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

Collision-Induced Transitions within Excited Levels of Neon

Joel H. Parks, Ali Javan

Published Aug 30, 1965• 44 citations
Publisher

Abstract

The interaction of an intense optical-maser field with excited atoms in a gas discharge leads to a considerable change in the population of those levels which are resonant at the maser frequency. This will cause a change in the population of other levels that are connected to the maser levels through collision-induced nonradiative as well as radiative transitions. Using the 1.15-\ensuremath{\mu} optical maser, these effects have been studied in detail for the $2s$ levels of neon where the changes are completely due to collisions. By analyzing the intensity changes in spontaneous emission originating from a gas-discharge cell placed within the maser resonator, we have observed the approach to a partial thermalization of two closely spaced levels. In this way we have been able to obtain the atomic-collision cross section for excitation transfer between the $2{s}_{2}$ and $2{s}_{3}$ levels. In pure neon this has been found to be ${\ensuremath{\sigma}}_{23}=(2.3\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$. For a helium-neon mixture the measured cross section is ${\ensuremath{\sigma}}_{23}=(1.8\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$. The experimental method used to determine these cross sections eliminates the uncertainties caused by the effects of electron-atom collisions and radiative cascade. These techniques also yield the ratio of the Einstein coefficients for the transitions $2{s}_{2}\ensuremath{\rightarrow}2{p}_{10}$ and $2{s}_{3}\ensuremath{\rightarrow}2{p}_{10}$. The measured ratio is $\frac{{A}_{2}}{{A}_{3}}=3.0\ifmmode\pm\else\textpm\fi{}0.4$.

DOI
10.1103/physrev.139.a1351

Related papers

Collision-Induced Mixing in the 2P3 Levels of Helium

L. D. Schearer

The cross section for the transfer of excitation from the $2^{3}P_{0}$ level of helium to the $2^{3}P_{1}$ and $2^{3}P_{2}$ levels as a result of collisions with the ground-state helium atom ($1^{1}S_{0}$) has been measured with a conventional resonance-fluorescence technique. A ${\mathrm{He}}^{4}$ source excited the $2^{3}S_{1}\ensuremath{-}2^{3}P_{0}$ transition in a ${\mathrm{He}}^{3}$ absorption cell. The scattered light was examined with a high-resolution grating spectrometer and the ratio of the $2^{3}P_{0}\ensuremath{\rightarrow}2^{3}S_{1}$ to the $2^{3}P_{1,2}\ensuremath{\rightarrow}2^{3}S_{1}$ intensities was measured as a function of cell pressure from 0.05 to 10 Torr. The cross section for collision-induced transitions out of the $2^{3}P_{0}$ level is found to be (68\ifmmode\pm\else\textpm\fi{}3) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$ at room temperature.

Physical Review•Aug 5, 1967•29 citations

Collisional excitation transfer in optically pumped atomic copper vapor

Nackchin Sung, Jin J. Kim

Recently we reported the observation of stimulated emission in atomic copper vapor that is excited by a resonant tunable laser beam.1 One important result obtained in the experiment is that the two upper levels involved in the laser transitions of the atomic copper vapor are collisionally mixed in stimulated emission. This observation is particularly important for studies of high-pressure transverse-discharge copper vapor lasers. We conducted an optical pumping experiment to measure the collisional mixing cross sections (CMCSs) below the threshold of stimulated emission. We observed all four transitions: 2P1/2−2S1/2 (327.4 nm); 2P3/2−2S1/2 (324.8 nm); 2P1/2−2D3/2 (578.2 nm); and 2P3/2−2D5/2 (510.6 nm), when either one of the two levels 2P3/2,1/2 was excited. From the measurements of the intensities of the resonantly excited and sensitized fluorescences, we estimate the CMCSs Q34(2P1/2→2P3/2) and Q43(2P1/2←2P3/2) at 2 × 10−16 and 1.3 × 10-16 cm2 for Cu + Ne collisions, respectively. We also measured the linewidths of the optically pumped green and yellow lasers as a function of the buffer gas pressure and of detuning of the pump frequency. We observe that the linewidths change in an interesting way, which can be explained in terms of the gain narrowing.

Annual Meeting Optical Society of America•Jan 1, 1988•0 citations

Inelastic Collisions between Excited Alkali Atoms and Molecules. I. Sensitized Fluorescence and Quenching in Cs- N2 and Cs- H2 Systems

D. A. McGillis, L. Krause

Excitation transfer between the $6 ^{2}P_{\frac{1}{2}}$ and $6 ^{2}P_{\frac{3}{2}}$ resonance states in cesium, induced by Cs-${\mathrm{N}}_{2}$ and Cs-${\mathrm{H}}_{2}$ collisions, was observed in the first experiment of its kind, in which techniques of sensitized fluorescence are used to investigate collisional mixing between resonance states of alkali atoms in mixtures with molecular gases. The cesium-vapor-gas system, in which the cesium vapor pressure was low enough to avoid radiation trapping, was irradiated with a single component of the resonance doublet. The fluorescent light, which contained both components of the doublet, was monitored at right angles to the direction of excitation. Measurements of relative intensities of the fluorescent components yielded the following cross sections for excitation transfer and for quenching of resonance radiation. For Cs-${\mathrm{N}}_{2}$ collisions: ${Q}_{12}(^{2}P_{\frac{1}{2}}\ensuremath{\rightarrow}^{2}P_{\frac{3}{2}})=3.6$ ${\mathrm{\AA{}}}^{2}$, ${Q}_{21}(^{2}P_{\frac{1}{2}}\ensuremath{\leftarrow}^{2}P_{\frac{3}{2}})=16.2$ ${\mathrm{\AA{}}}^{2}$, ${Q}_{10}(^{2}S_{\frac{1}{2}}\ensuremath{\leftarrow}^{2}P_{\frac{1}{2}})=55.2$ ${\mathrm{\AA{}}}^{2}$, ${Q}_{20}(^{2}S_{\frac{1}{2}}\ensuremath{\leftarrow}^{2}P_{\frac{3}{2}})=63.5$ ${\mathrm{\AA{}}}^{2}$. For Cs-${\mathrm{H}}_{2}$ collisions: ${Q}_{12}=6.7$ ${\mathrm{\AA{}}}^{2}$, ${Q}_{21}=29.6$ ${\mathrm{\AA{}}}^{2}$, ${Q}_{10}=11.7$ ${\mathrm{\AA{}}}^{2}$, ${Q}_{20}=6.7$ ${\mathrm{\AA{}}}^{2}$. The large sizes of the excitation-transfer cross sections, which are comparable to the corresponding Cs-Cs cross sections, are attributed to resonances with transitions in the molecules.

Physical Review•Jan 5, 1967•41 citations

Inelastic Collisions between Excited Alkali Atoms and Molecules. II. The Quenching of Sodium Resonance Radiation by N2 , H2 , HD, and D2

B P Kibble, G. H. Copley, L. Krause

The cross sections for quenching collisions between excited sodium atoms and ${\mathrm{N}}_{2}$, ${\mathrm{H}}_{2}$, HD, and ${\mathrm{D}}_{2}$ molecules in their electronic ground states have been determined using a delayed-coincidence method. The sodium atoms in mixtures with the gases were excited with 20-nsec pulses of NaD radiation, and the delays between the exciting and fluorescent pulses were measured with a time-to-pulse-height converter. The resulting pulse-height spectra, which were accummulated in a 400-channel kicksorter, yielded the effective lifetimes ${\ensuremath{\tau}}^{\ensuremath{'}}$ of the sodium resonance state, which are shorter than the natural lifetime $\ensuremath{\tau}$ because of the nonradiative decay induced in collisions with the molecules. The cross sections for collisions with ${\mathrm{N}}_{2}$, ${\mathrm{H}}_{2}$, HD, and ${\mathrm{D}}_{2}$, obtained from an analysis of the dependence of ${\ensuremath{\tau}}^{\ensuremath{'}}$ on the gas pressures, are 30.4\ifmmode\pm\else\textpm\fi{}1.2, 16.2\ifmmode\pm\else\textpm\fi{}0.3, 11.6\ifmmode\pm\else\textpm\fi{}0.4, and 9.8\ifmmode\pm\else\textpm\fi{}0.3 ${\mathrm{\AA{}}}^{2}$, respectively.

Physical Review•Jul 5, 1967•48 citations

7D322−7D522 excitation transfer in rubidium induced in collisions with ground-state Rb and noble-gas atoms

J. Wolnikowski, J. B. Atkinson, J. Supronowicz +1 more

Cross sections for $7^{2}D_{\frac{3}{2}}\ensuremath{\leftrightarrow}7^{2}D_{\frac{5}{2}}$ transfer in Rb, induced in collisions with He, Ne, Ar, and with ground-state Rb atoms, have been determined using methods of atomic fluorescence. Rb vapor, pure or mixed with a noble gas, was irradiated in a glass fluorescence cell with pulses of 660-nm radiation from a ${\mathrm{N}}_{2}$-laser-pumped dye laser, populating one of the $^{2}D$ states by two-photon absorption. The resulting fluorescence included a direct component emitted in the decay of the optically excited state and a sensitized component arising from the collisionally populated state. Relative intensities of the components yielded the cross sections for $7^{2}D$ mixing: $Q(^{2}D_{\frac{3}{2}}\ensuremath{\rightarrow}^{2}D_{\frac{5}{2}})=8.8,6.5,10.4, \mathrm{and} 30$; $Q(^{2}D_{\frac{3}{2}}\ensuremath{\leftarrow}^{2}D_{\frac{5}{2}})=5.8,4.0,6.9, \mathrm{and} 18$, in units of ${10}^{\ensuremath{-}14}$ ${\mathrm{cm}}^{2}$ for He, Ne, Ar, and Rb, respectively. Cross sections for the effective quenching of the $^{2}D$ states were also determined.

Physical Review A•May 1, 1982•13 citations

Collision-Induced Mixing in the First Excited States of Sodium and Potassium

J. A. Jordan, P. A. Franken

The cross sections for the collision-induced transfer of excitation from the $^{2}P_{\frac{3}{2}}$ level to the $^{2}P_{\frac{1}{2}}$ level of the first excited states of the alkali atoms have been measured for several alkali-noble gas systems. The cross sections were determined with a conventional resonance fluorescence technique in which the radiation from a spectral source was absorbed and re-emitted by an alkali vapor at low pressure (\ensuremath{\sim}${10}^{\ensuremath{-}6}$ Torr), and the scattered light analyzed with a scanning spectrometer. Provision was made for the introduction of various noble gases at controlled pressures into the alkali vapor. The determined cross sections are (in units of ${10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$): Na-He, 41.1\ifmmode\pm\else\textpm\fi{}2.9; Na-Ne, 36.1\ifmmode\pm\else\textpm\fi{}2.5; Na-Ar, 64.6\ifmmode\pm\else\textpm\fi{}5.2; Na-Kr, 68.2\ifmmode\pm\else\textpm\fi{}5.5; Na-Xe, 61.8\ifmmode\pm\else\textpm\fi{}4.9; K-He, 52.8\ifmmode\pm\else\textpm\fi{}5.8; K-Ne, 14.0\ifmmode\pm\else\textpm\fi{}1.2; K-Ar, 34.0\ifmmode\pm\else\textpm\fi{}3.1. The quoted errors are estimated 70% confidence intervals. The measurements are compared with other experimental results and with various estimated cross sections.

Physical Review•Feb 4, 1966•39 citations
The interaction of an intense optical-maser field with excited atoms in a gas discharge leads to a considerable change in the population of those levels which are resonant at the maser frequency. This will cause a change in the population of other levels that are connected to the maser levels through collision-induced nonradiative as well as radiative transitions. Using the 1.15-\ensuremath{\mu} optical maser, these effects have been studied in detail for the 2s2s2s levels of neon where the changes are completely due to collisions. By analyzing the intensity changes in spontaneous emission originating from a gas-discharge cell placed within the maser resonator, we have observed the approach to a partial thermalization of two closely spaced levels. In this way we have been able to obtain the atomic-collision cross section for excitation transfer between the 2s22{s}_{2}2s2​ and 2s32{s}_{3}2s3​ levels. In pure neon this has been found to be \ensuremathσ23=(2.3\ifmmode±\else\textpm\fi0.3)\ifmmode×\else\texttimes\fi10\ensuremath−16{\ensuremath{\sigma}}_{23}=(2.3\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}\ensuremathσ23​=(2.3\ifmmode±\else\textpm\fi0.3)\ifmmode×\else\texttimes\fi10\ensuremath−16 cm2{\mathrm{cm}}^{2}cm2. For a helium-neon mixture the measured cross section is \ensuremathσ23=(1.8\ifmmode±\else\textpm\fi0.3)\ifmmode×\else\texttimes\fi10\ensuremath−16{\ensuremath{\sigma}}_{23}=(1.8\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}\ensuremathσ23​=(1.8\ifmmode±\else\textpm\fi0.3)\ifmmode×\else\texttimes\fi10\ensuremath−16 cm2{\mathrm{cm}}^{2}cm2. The experimental method used to determine these cross sections eliminates the uncertainties caused by the effects of electron-atom collisions and radiative cascade. These techniques also yield the ratio of the Einstein coefficients for the transitions 2s2\ensuremath→2p102{s}_{2}\ensuremath{\rightarrow}2{p}_{10}2s2​\ensuremath→2p10​ and 2s3\ensuremath→2p102{s}_{3}\ensuremath{\rightarrow}2{p}_{10}2s3​\ensuremath→2p10​. The measured ratio is A2A3=3.0\ifmmode±\else\textpm\fi0.4\frac{{A}_{2}}{{A}_{3}}=3.0\ifmmode\pm\else\textpm\fi{}0.4A3​A2​​=3.0\ifmmode±\else\textpm\fi0.4.
The cross section for the transfer of excitation from the 23P02^{3}P_{0}23P0​ level of helium to the 23P12^{3}P_{1}23P1​ and 23P22^{3}P_{2}23P2​ levels as a result of collisions with the ground-state helium atom (11S01^{1}S_{0}11S0​) has been measured with a conventional resonance-fluorescence technique. A He4{\mathrm{He}}^{4}He4 source excited the $2^{3}S_{1}\ensuremath{-}2^{3}P_{0}$ transition in a He3{\mathrm{He}}^{3}He3 absorption cell. The scattered light was examined with a high-resolution grating spectrometer and the ratio of the $2^{3}P_{0}\ensuremath{\rightarrow}2^{3}S_{1}$ to the $2^{3}P_{1,2}\ensuremath{\rightarrow}2^{3}S_{1}$ intensities was measured as a function of cell pressure from 0.05 to 10 Torr. The cross section for collision-induced transitions out of the 23P02^{3}P_{0}23P0​ level is found to be (68\ifmmode\pm\else\textpm\fi{}3) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}16}$ cm2{\mathrm{cm}}^{2}cm2 at room temperature.
Recently we reported the observation of stimulated emission in atomic copper vapor that is excited by a resonant tunable laser beam.1 One important result obtained in the experiment is that the two upper levels involved in the laser transitions of the atomic copper vapor are collisionally mixed in stimulated emission. This observation is particularly important for studies of high-pressure transverse-discharge copper vapor lasers. We conducted an optical pumping experiment to measure the collisional mixing cross sections (CMCSs) below the threshold of stimulated emission. We observed all four transitions: 2P1/2−2S1/2 (327.4 nm); 2P3/2−2S1/2 (324.8 nm); 2P1/2−2D3/2 (578.2 nm); and 2P3/2−2D5/2 (510.6 nm), when either one of the two levels 2P3/2,1/2 was excited. From the measurements of the intensities of the resonantly excited and sensitized fluorescences, we estimate the CMCSs Q34(2P1/2→2P3/2) and Q43(2P1/2←2P3/2) at 2 × 10−16 and 1.3 × 10-16 cm2 for Cu + Ne collisions, respectively. We also measured the linewidths of the optically pumped green and yellow lasers as a function of the buffer gas pressure and of detuning of the pump frequency. We observe that the linewidths change in an interesting way, which can be explained in terms of the gain narrowing.
Excitation transfer between the 62P126 ^{2}P_{\frac{1}{2}}62P21​​ and 62P326 ^{2}P_{\frac{3}{2}}62P23​​ resonance states in cesium, induced by Cs-N2{\mathrm{N}}_{2}N2​ and Cs-H2{\mathrm{H}}_{2}H2​ collisions, was observed in the first experiment of its kind, in which techniques of sensitized fluorescence are used to investigate collisional mixing between resonance states of alkali atoms in mixtures with molecular gases. The cesium-vapor-gas system, in which the cesium vapor pressure was low enough to avoid radiation trapping, was irradiated with a single component of the resonance doublet. The fluorescent light, which contained both components of the doublet, was monitored at right angles to the direction of excitation. Measurements of relative intensities of the fluorescent components yielded the following cross sections for excitation transfer and for quenching of resonance radiation. For Cs-N2{\mathrm{N}}_{2}N2​ collisions: ${Q}_{12}(^{2}P_{\frac{1}{2}}\ensuremath{\rightarrow}^{2}P_{\frac{3}{2}})=3.6$ A˚2{\mathrm{\AA{}}}^{2}A˚2, ${Q}_{21}(^{2}P_{\frac{1}{2}}\ensuremath{\leftarrow}^{2}P_{\frac{3}{2}})=16.2$ A˚2{\mathrm{\AA{}}}^{2}A˚2, ${Q}_{10}(^{2}S_{\frac{1}{2}}\ensuremath{\leftarrow}^{2}P_{\frac{1}{2}})=55.2$ A˚2{\mathrm{\AA{}}}^{2}A˚2, ${Q}_{20}(^{2}S_{\frac{1}{2}}\ensuremath{\leftarrow}^{2}P_{\frac{3}{2}})=63.5$ A˚2{\mathrm{\AA{}}}^{2}A˚2. For Cs-H2{\mathrm{H}}_{2}H2​ collisions: Q12=6.7{Q}_{12}=6.7Q12​=6.7 A˚2{\mathrm{\AA{}}}^{2}A˚2, Q21=29.6{Q}_{21}=29.6Q21​=29.6 A˚2{\mathrm{\AA{}}}^{2}A˚2, Q10=11.7{Q}_{10}=11.7Q10​=11.7 A˚2{\mathrm{\AA{}}}^{2}A˚2, Q20=6.7{Q}_{20}=6.7Q20​=6.7 A˚2{\mathrm{\AA{}}}^{2}A˚2. The large sizes of the excitation-transfer cross sections, which are comparable to the corresponding Cs-Cs cross sections, are attributed to resonances with transitions in the molecules.
The cross sections for quenching collisions between excited sodium atoms and N2{\mathrm{N}}_{2}N2​, H2{\mathrm{H}}_{2}H2​, HD, and D2{\mathrm{D}}_{2}D2​ molecules in their electronic ground states have been determined using a delayed-coincidence method. The sodium atoms in mixtures with the gases were excited with 20-nsec pulses of NaD radiation, and the delays between the exciting and fluorescent pulses were measured with a time-to-pulse-height converter. The resulting pulse-height spectra, which were accummulated in a 400-channel kicksorter, yielded the effective lifetimes ${\ensuremath{\tau}}^{\ensuremath{'}}$ of the sodium resonance state, which are shorter than the natural lifetime $\ensuremath{\tau}$ because of the nonradiative decay induced in collisions with the molecules. The cross sections for collisions with N2{\mathrm{N}}_{2}N2​, H2{\mathrm{H}}_{2}H2​, HD, and D2{\mathrm{D}}_{2}D2​, obtained from an analysis of the dependence of ${\ensuremath{\tau}}^{\ensuremath{'}}$ on the gas pressures, are 30.4\ifmmode\pm\else\textpm\fi{}1.2, 16.2\ifmmode\pm\else\textpm\fi{}0.3, 11.6\ifmmode\pm\else\textpm\fi{}0.4, and 9.8\ifmmode\pm\else\textpm\fi{}0.3 A˚2{\mathrm{\AA{}}}^{2}A˚2, respectively.
Cross sections for $7^{2}D_{\frac{3}{2}}\ensuremath{\leftrightarrow}7^{2}D_{\frac{5}{2}}$ transfer in Rb, induced in collisions with He, Ne, Ar, and with ground-state Rb atoms, have been determined using methods of atomic fluorescence. Rb vapor, pure or mixed with a noble gas, was irradiated in a glass fluorescence cell with pulses of 660-nm radiation from a N2{\mathrm{N}}_{2}N2​-laser-pumped dye laser, populating one of the 2D^{2}D2D states by two-photon absorption. The resulting fluorescence included a direct component emitted in the decay of the optically excited state and a sensitized component arising from the collisionally populated state. Relative intensities of the components yielded the cross sections for 72D7^{2}D72D mixing: $Q(^{2}D_{\frac{3}{2}}\ensuremath{\rightarrow}^{2}D_{\frac{5}{2}})=8.8,6.5,10.4, \mathrm{and} 30$; $Q(^{2}D_{\frac{3}{2}}\ensuremath{\leftarrow}^{2}D_{\frac{5}{2}})=5.8,4.0,6.9, \mathrm{and} 18$, in units of ${10}^{\ensuremath{-}14}$ cm2{\mathrm{cm}}^{2}cm2 for He, Ne, Ar, and Rb, respectively. Cross sections for the effective quenching of the 2D^{2}D2D states were also determined.
The cross sections for the collision-induced transfer of excitation from the 2P32^{2}P_{\frac{3}{2}}2P23​​ level to the 2P12^{2}P_{\frac{1}{2}}2P21​​ level of the first excited states of the alkali atoms have been measured for several alkali-noble gas systems. The cross sections were determined with a conventional resonance fluorescence technique in which the radiation from a spectral source was absorbed and re-emitted by an alkali vapor at low pressure (\ensuremath{\sim}${10}^{\ensuremath{-}6}$ Torr), and the scattered light analyzed with a scanning spectrometer. Provision was made for the introduction of various noble gases at controlled pressures into the alkali vapor. The determined cross sections are (in units of ${10}^{\ensuremath{-}16}$ cm2{\mathrm{cm}}^{2}cm2): Na-He, 41.1\ifmmode\pm\else\textpm\fi{}2.9; Na-Ne, 36.1\ifmmode\pm\else\textpm\fi{}2.5; Na-Ar, 64.6\ifmmode\pm\else\textpm\fi{}5.2; Na-Kr, 68.2\ifmmode\pm\else\textpm\fi{}5.5; Na-Xe, 61.8\ifmmode\pm\else\textpm\fi{}4.9; K-He, 52.8\ifmmode\pm\else\textpm\fi{}5.8; K-Ne, 14.0\ifmmode\pm\else\textpm\fi{}1.2; K-Ar, 34.0\ifmmode\pm\else\textpm\fi{}3.1. The quoted errors are estimated 70% confidence intervals. The measurements are compared with other experimental results and with various estimated cross sections.