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

Optics Express

Collisional mixing and quenching cross sections of Cs 62P levels with methane, ethane, and propane

Masamori Endo, Hiroki Nagaoka, Fumio Wani

Published Nov 25, 2021• 4 citations
Publisher

Abstract

Mixing cross sections of Cs between the 62P1/2 and 62P3/2 levels and quenching cross sections from these levels to the ground state 62S1/2 were measured, with methane, ethane, and propane as collision partners. We excited Cs to the 6P3/2 level with a tunable nanosecond pulse laser and measured the fluorescence at the 62P1/2 level. The measured mixing cross sections with methane, ethane, and propane were (1.39 ± 0.16), (5.67 ± 0.85), and (7.91 ± 0.93)×10−15 cm2, respectively, and the statistically averaged quenching cross sections were (1.5 ± 0.25), (10 ± 2.0), and (25 ± 5.3)×10−18 cm2, respectively. The quenching cross section of Cs-propane is reported for the first time.

DOI
10.1364/oe.446192

Related papers

Radiation and Collision Energy Transfer of Excitated Cs(6P) Atoms Mixed with He

Yifan Shen

By applying the laser absorption and fluorescence method,the cross sections for the fine structure mixing and quenching of the Cs(6P) state,induced by collision with He atoms,have been measured.Cesium atoms were optically excited to the 6P3/2 state.The excited atom density and spatial distribution were mapped by monitoring the absorption of a counterpropagating single mode laser beam,which was tuned to the 6PJ→8S1/2 transitions.The effective radiative rates were calculated for the 6PJ→6S transitions.The fluorescence intensity I895 of the sensitized 6P1/2→6S1/2 emission was measured as a function of He density in the range 0.5×1018～4×1018cm-3 at constant temperature T=337 K.It was found that the quantity N/I895 exhibited a parabolic dependence on N,confirming that the quenching of the 6PJ states was due to collision with He atoms,not ground state Cs atoms.The coefficients of the second-order polynomial fitted through the measured data yielded the cross sections σ3/2→1/2=(1.46±0.51)×10-19 cm2 and σD=(2.28±0.80)×10-18 cm2 for the 6PJ fine structure mixing and quenching,respectively,due to collision with He atoms.

Chinese Journal of Lasers•Jan 1, 2007•0 citations

[Radiative transport and collisional transfer of excitation energy in Cs(6P) atoms mixed with N2].

Fanxin Meng, Qin Chen, Kang Dai +1 more

Applying the CW laser absorption and fluorescence method, the cross sections for the fine structure mixing and quenching of the Cs(6P) state, induced by collision with N2 molecules, were measured. Cesium atoms were optically excited to the 6P3/2 state. The excited atom density and spatial distribution were mapped by monitoring the absorption of a counterpropagating single mode laser beam, tuned to the 6P1 --> 8S(1/2) transitions, which could be translated parallel to the pump beam. The transmission factors, which describe the average probability that photons emitted within the fluorescence detection region can pass through the optically thick vapor without being absorbed, were calculated for 6P --> 6S(1/2) transitions. The N2 caused line broadening and therefore increased the effective pumping rate and radiative rates. The effective radiative rates were calculated for the 6P(J) --> 6S transitions. The fluorescence intensity I895 of the sensitized 6P(1/2) --> 6S(1/2) emission was measured as a function of N2 density in the range 2 x 10(16) < N < 1.4 x 10(17) cm(-3) at a constant temperature T = 337 K, which produced cesium density N0 = 1.25 x 10(12) cm(-3). The transparency of the cell was obtained by the absorption of light beam passing the cell. The transparency is not a simple function of N2 density. It was found that the quantity N/I895 (I895 being corrected for the cell transparency) exhibited a parabolic dependence on N, confirming that the quenching of the 6P(J) states is due to collision with N2 molecules instead of Cs ground state atoms. The coefficients of the second-order polynomial fitted through the measured data yielded the cross sections sigma3/2 --> 1/2 = (0.42 +/- 0.17) x 10(-16) cm2 and sigmaD = (1.31 +/- 0.52) x 10(-16) cm2 for the 6P(J) fine-structure mixing and quenching, respectively, due to collision with N2 molecules. The quenching rate coefficient is about 3 times larger than the rate coefficient for the fine-structure mixing. Our values for these cross sections are in agreement, within combined error bars, with the values we have recently obtained under different experimental conditions.

•May 1, 2008•0 citations

Cross sections for Cs(6D_J)→Cs(7P_(J~′)) collisional transfer processes induced by H_2

Yifan Shen

Cs vapor was created in a resistively heated,cross-shaped stainless-steel heat-pipe oven with quartz windows.H2 gas filled in the cell for use both as a buffer gas and as a reaction partner.Cs atoms were excited to 6D3/2 state by two-photon absorption.The 7P1/2 and 7P3/2 were populated by the radiative and collisional 6DJ→7PJ′ transition.The cross sections for 6DJ7PJ′ transfer induced by collision with H2 molecules have been determined using methods of atomic fluorescence.The resulting fluorescence included a direct component emitted in the decay of the optically excited state and sensitive component arising from collisionally populated states.The time-integrated fluorescence intensities for atomic transitions 6D5/2→6P3/2,6D3/2→6P3/2,7P3/2→6S1/2 and 7P1/2→6S1/2 were measured at the defferent H2 densities.The relative time-integrated population densities were obtained as a function of H2 densities.By the set of the rate equations,the cross-sections have been determined to be σ6D3/27P3/2=(3.1±0.8)×10-16cm2,σ6D3/27P1/2=(1.7±0.4)×10-16cm2,σ6D5/27P3/2=(1.5±0.4)×10-16cm2 and σ6D5/27P1/2=(1.3±0.3)×10-16 cm2.The cross sections for quenching of 7PJ′ by H2 are(2.5±0.6)×10-16 cm2(for 7P3/2) and(4.0±1.0)×10-16 cm2(for 7P1/2).Evidence suggests that the substantial fraction of quenching cross section is reactive.The relative reactivity with H2 is an order 7P1/27P3/2.

Jiguang zazhi•Jan 1, 2010•0 citations

Caesium 6P fine-structure mixing and quenching induced by collisions with ground-state caesium atoms and molecules

Mladen Movre, Vlasta Horvatić, Cedomil Vadla

Applying the cw laser fluorescence method, the cross sections for the fine structure mixing and quenching of the Cs 6P state, induced by collisions with ground-state caesium atoms and molecules, have been measured. Caesium atoms were optically excited to the 5D J states via quadrupole-allowed 6S 1/2 5D J transitions, while the resonance states were populated by the radiative and collisional 5D J 6P J transitions. The relative populations of the Cs 6P J sublevels, as well as ratio of the 5D 3/2 to 6P 3/2 populations, were measured as a function of the caesium ground-state number density. From these measurements we obtained the cross section of (14±5) × 10 -16 cm 2 at T = 585 K for the process Cs(6P 1/2 ) Cs(6P 3/2 ) induced by collisions with ground-state caesium atoms. The applied experimental approach enabled the determination of the effective spontaneous rates for the 6P J states which are in agreement with the predictions of Holstein's theory. The cross sections for quenching of 6P J by caesium atoms and molecules were measured at T = 635 K and the obtained values are (1.6±1.4) × 10 -16 cm 2 and (1210±260) × 10 -16 cm 2 , respectively. Using recently calculated Cs*+Cs potentials we performed an analysis which shows a good agreement between the measured values and the theoretical estimates.

Journal of Physics B Atomic Molecular and Optical Physics•Sep 17, 1999•8 citations

Quenching of Cesium Resonance Radiation by Helium

John N. Dodd, E. A. Enemark, Alan Gallagher

Using the phase-shift technique to measure excited-state lifetimes, upper limits of 1.5 × 10−14 cm3/sec and 3 × 10−14 cm3/sec have been established for the Cs(62P1/2re3/2) + He → Cs(62S1/2) + He quenching rate constants at 350° and 820°K. (In “cross-section” units these are equivalent to 10−19 cm2 upper limits.) The natural lifetimes were measured to be 30.8 ± 1.5 × 10−9 sec and 35.2 ± 1.5 × 10−9 sec for the Cs 62P3/2 and 62P1/2 states.

The Journal of Chemical Physics•Jun 1, 1969•26 citations

[Experimental evaluation of the cross sections in Cs (6D(1/2)) + Cs(6S(1/2)) inelastic collisions].

Qi-cun Guo, Hongping Wu, Li-kui Kang +3 more

At a Cs density higher than 9 x 10(14) cm(-3), cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from an YAG-laser-pumped OPO laser, populating 6D(5/2) state by two-photon absorption. Energy transfer in Cs6(D(5/2)) + Cs (6S) collisions was studied using methods of atomic fluorescence. At the different Cs densities, we have measured the time-integrated intensities of the components and fitted a three-state rate equation model to obtain the cross sections. The experimental points were fitted to a straight line very well. The authors converted the gradient and intercept into cross sections. The cross section for 6D(5/2)-->6D(3/2) transfer is (2.1 +/- 0.4) x 10(14) cm2. The cross section for excitation transfer out of the 6D doublet is sigmaQ = (1.6 +/- 0.4) x 10(-14) cm2. The cross section on contains information on reverse energy pooling collisions [i.e., Cs(6D(3/2)) + Cs (6S(1/2))-->Cs(6P) + 6Cs(P)] and contribution from mining in 6Dj-->7P(J'), This latter contribution could be subtracted out using the results of a second experiment. At a Cs density lower than 6.0 x 10(12) cm3, the laser was used to pump the 6D(3/2) and 6D(5/2) states, respectively. The resulting fluorescence included the direct component emitted in the decay of the 6D(J) state and the sensitized component arising from the collisionally populated 7P(J') state. Relative intensities of the components yielded the cross sections. The cross-sections for the processes Cs(6D(5/2)) + Cs(6S(1/2))-->Cs(7P(J')) + Cs(6S(1/2)) are (1.6 +/- 0.5) x 10(-15) cm2. for J'= 3/2 and (6.5 +/- 2.1) x 10(-16) cm2, for J' = 1/2, respectively. The cross-sections for the processes Cs(6D(3/2) + Cs(6S(1/2))-->Cs (7P(J')) + Cs(6S(1/2)) are (1.9 +/- 0.6) x 10(-15) cm2. for J' = 3/2 and (7.6 + 2.4) x 10(-16) cm2, for J' = 1/2, respectively. The 6D(J) -->7P(J'), energy transfer rate coefficient is small. The total quenching rate coefficient out of the 6D(J) state is much larger. Evidence suggests that the quenching of the 6D(J) state is caused predominantly by reverse energy-pooling process. The cross section for this process, i.e., Cs(6D(3/2))+Cs(6S(1/2))-->Cs(6P) + Cs(6P) is (1.3 +/- 0.4) x 10(-14) cm2.

•Sep 1, 2009•0 citations
Mixing cross sections of Cs between the 62P1/2 and 62P3/2 levels and quenching cross sections from these levels to the ground state 62S1/2 were measured, with methane, ethane, and propane as collision partners. We excited Cs to the 6P3/2 level with a tunable nanosecond pulse laser and measured the fluorescence at the 62P1/2 level. The measured mixing cross sections with methane, ethane, and propane were (1.39 ± 0.16), (5.67 ± 0.85), and (7.91 ± 0.93)×10−15 cm2, respectively, and the statistically averaged quenching cross sections were (1.5 ± 0.25), (10 ± 2.0), and (25 ± 5.3)×10−18 cm2, respectively. The quenching cross section of Cs-propane is reported for the first time.
By applying the laser absorption and fluorescence method,the cross sections for the fine structure mixing and quenching of the Cs(6P) state,induced by collision with He atoms,have been measured.Cesium atoms were optically excited to the 6P3/2 state.The excited atom density and spatial distribution were mapped by monitoring the absorption of a counterpropagating single mode laser beam,which was tuned to the 6PJ→8S1/2 transitions.The effective radiative rates were calculated for the 6PJ→6S transitions.The fluorescence intensity I895 of the sensitized 6P1/2→6S1/2 emission was measured as a function of He density in the range 0.5×1018～4×1018cm-3 at constant temperature T=337 K.It was found that the quantity N/I895 exhibited a parabolic dependence on N,confirming that the quenching of the 6PJ states was due to collision with He atoms,not ground state Cs atoms.The coefficients of the second-order polynomial fitted through the measured data yielded the cross sections σ3/2→1/2=(1.46±0.51)×10-19 cm2 and σD=(2.28±0.80)×10-18 cm2 for the 6PJ fine structure mixing and quenching,respectively,due to collision with He atoms.
Applying the CW laser absorption and fluorescence method, the cross sections for the fine structure mixing and quenching of the Cs(6P) state, induced by collision with N2 molecules, were measured. Cesium atoms were optically excited to the 6P3/2 state. The excited atom density and spatial distribution were mapped by monitoring the absorption of a counterpropagating single mode laser beam, tuned to the 6P1 --> 8S(1/2) transitions, which could be translated parallel to the pump beam. The transmission factors, which describe the average probability that photons emitted within the fluorescence detection region can pass through the optically thick vapor without being absorbed, were calculated for 6P --> 6S(1/2) transitions. The N2 caused line broadening and therefore increased the effective pumping rate and radiative rates. The effective radiative rates were calculated for the 6P(J) --> 6S transitions. The fluorescence intensity I895 of the sensitized 6P(1/2) --> 6S(1/2) emission was measured as a function of N2 density in the range 2 x 10(16) < N < 1.4 x 10(17) cm(-3) at a constant temperature T = 337 K, which produced cesium density N0 = 1.25 x 10(12) cm(-3). The transparency of the cell was obtained by the absorption of light beam passing the cell. The transparency is not a simple function of N2 density. It was found that the quantity N/I895 (I895 being corrected for the cell transparency) exhibited a parabolic dependence on N, confirming that the quenching of the 6P(J) states is due to collision with N2 molecules instead of Cs ground state atoms. The coefficients of the second-order polynomial fitted through the measured data yielded the cross sections sigma3/2 --> 1/2 = (0.42 +/- 0.17) x 10(-16) cm2 and sigmaD = (1.31 +/- 0.52) x 10(-16) cm2 for the 6P(J) fine-structure mixing and quenching, respectively, due to collision with N2 molecules. The quenching rate coefficient is about 3 times larger than the rate coefficient for the fine-structure mixing. Our values for these cross sections are in agreement, within combined error bars, with the values we have recently obtained under different experimental conditions.
Cs vapor was created in a resistively heated,cross-shaped stainless-steel heat-pipe oven with quartz windows.H2 gas filled in the cell for use both as a buffer gas and as a reaction partner.Cs atoms were excited to 6D3/2 state by two-photon absorption.The 7P1/2 and 7P3/2 were populated by the radiative and collisional 6DJ→7PJ′ transition.The cross sections for 6DJ7PJ′ transfer induced by collision with H2 molecules have been determined using methods of atomic fluorescence.The resulting fluorescence included a direct component emitted in the decay of the optically excited state and sensitive component arising from collisionally populated states.The time-integrated fluorescence intensities for atomic transitions 6D5/2→6P3/2,6D3/2→6P3/2,7P3/2→6S1/2 and 7P1/2→6S1/2 were measured at the defferent H2 densities.The relative time-integrated population densities were obtained as a function of H2 densities.By the set of the rate equations,the cross-sections have been determined to be σ6D3/27P3/2=(3.1±0.8)×10-16cm2,σ6D3/27P1/2=(1.7±0.4)×10-16cm2,σ6D5/27P3/2=(1.5±0.4)×10-16cm2 and σ6D5/27P1/2=(1.3±0.3)×10-16 cm2.The cross sections for quenching of 7PJ′ by H2 are(2.5±0.6)×10-16 cm2(for 7P3/2) and(4.0±1.0)×10-16 cm2(for 7P1/2).Evidence suggests that the substantial fraction of quenching cross section is reactive.The relative reactivity with H2 is an order 7P1/27P3/2.
Applying the cw laser fluorescence method, the cross sections for the fine structure mixing and quenching of the Cs 6P state, induced by collisions with ground-state caesium atoms and molecules, have been measured. Caesium atoms were optically excited to the 5D J states via quadrupole-allowed 6S 1/2 5D J transitions, while the resonance states were populated by the radiative and collisional 5D J 6P J transitions. The relative populations of the Cs 6P J sublevels, as well as ratio of the 5D 3/2 to 6P 3/2 populations, were measured as a function of the caesium ground-state number density. From these measurements we obtained the cross section of (14±5) × 10 -16 cm 2 at T = 585 K for the process Cs(6P 1/2 ) Cs(6P 3/2 ) induced by collisions with ground-state caesium atoms. The applied experimental approach enabled the determination of the effective spontaneous rates for the 6P J states which are in agreement with the predictions of Holstein's theory. The cross sections for quenching of 6P J by caesium atoms and molecules were measured at T = 635 K and the obtained values are (1.6±1.4) × 10 -16 cm 2 and (1210±260) × 10 -16 cm 2 , respectively. Using recently calculated Cs*+Cs potentials we performed an analysis which shows a good agreement between the measured values and the theoretical estimates.
At a Cs density higher than 9 x 10(14) cm(-3), cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from an YAG-laser-pumped OPO laser, populating 6D(5/2) state by two-photon absorption. Energy transfer in Cs6(D(5/2)) + Cs (6S) collisions was studied using methods of atomic fluorescence. At the different Cs densities, we have measured the time-integrated intensities of the components and fitted a three-state rate equation model to obtain the cross sections. The experimental points were fitted to a straight line very well. The authors converted the gradient and intercept into cross sections. The cross section for 6D(5/2)-->6D(3/2) transfer is (2.1 +/- 0.4) x 10(14) cm2. The cross section for excitation transfer out of the 6D doublet is sigmaQ = (1.6 +/- 0.4) x 10(-14) cm2. The cross section on contains information on reverse energy pooling collisions [i.e., Cs(6D(3/2)) + Cs (6S(1/2))-->Cs(6P) + 6Cs(P)] and contribution from mining in 6Dj-->7P(J'), This latter contribution could be subtracted out using the results of a second experiment. At a Cs density lower than 6.0 x 10(12) cm3, the laser was used to pump the 6D(3/2) and 6D(5/2) states, respectively. The resulting fluorescence included the direct component emitted in the decay of the 6D(J) state and the sensitized component arising from the collisionally populated 7P(J') state. Relative intensities of the components yielded the cross sections. The cross-sections for the processes Cs(6D(5/2)) + Cs(6S(1/2))-->Cs(7P(J')) + Cs(6S(1/2)) are (1.6 +/- 0.5) x 10(-15) cm2. for J'= 3/2 and (6.5 +/- 2.1) x 10(-16) cm2, for J' = 1/2, respectively. The cross-sections for the processes Cs(6D(3/2) + Cs(6S(1/2))-->Cs (7P(J')) + Cs(6S(1/2)) are (1.9 +/- 0.6) x 10(-15) cm2. for J' = 3/2 and (7.6 + 2.4) x 10(-16) cm2, for J' = 1/2, respectively. The 6D(J) -->7P(J'), energy transfer rate coefficient is small. The total quenching rate coefficient out of the 6D(J) state is much larger. Evidence suggests that the quenching of the 6D(J) state is caused predominantly by reverse energy-pooling process. The cross section for this process, i.e., Cs(6D(3/2))+Cs(6S(1/2))-->Cs(6P) + Cs(6P) is (1.3 +/- 0.4) x 10(-14) cm2.