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

Energy pooling in Na 3p−Na 3p collisions

Vikram S. Kushawaha, Jacob J. Leventhal

Published Dec 1, 1980• 45 citations
Publisher

Abstract

The formation of Na ($\mathrm{nl}$) and $\mathrm{Na}_{2}^{}{}_{}{}^{+}$ in sodium vapor (\ensuremath{\sim}${10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) irradiated by a single-frequency (20-MHz bandwidth) cw dye laser tuned to one of the $D$ lines has been studied. The dependence of product signal on laser power density suggests that Na $3p$-Na $3p$ energy pooling collisions are responsible for these species. Rate constants for specific reaction channels and temperature dependences of rate constants are also reported.

DOI
10.1103/physreva.22.2468

Related papers

Ionization and Energy Pooling in Laser-Excited Na Vapor

Gregory H. Bearman, Jacob J. Leventhal

We have observed ion formation (both ${\mathrm{Na}}^{+}$ and ${\mathrm{Na}}_{2}^{+}$) and radiation from high-lying Na states when low-density vapor (\ensuremath{\sim}${10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) is irradiated with a cw dye laser tuned to one of the $D$ lines. The ${\mathrm{Na}}^{+}$ ions probably result from photodissociation of ${\mathrm{Na}}_{2}^{+}$ formed by $\mathrm{Na}(3p)\ensuremath{-}\mathrm{Na}(3p)$ associative ionization, while the high-lying radiating states are formed in energy-pooling reactions.

Physical Review Letters•Oct 30, 1978•63 citations

[Energy pooling collisions between excited Na and K atoms].

Yifan Shen, Wei Li

Two different atomic species, sodium and potassium, are resonantly excited in a ceel by a CW dye laser and a potassium lamp, respectively. The density of the excited Na (3P) atoms in the cell is measured directly using the absorption-equivalent-width technique on the lines of the diffuse series. To isolate the heteronuclear contribution in the fluorescence spectrum, a modulation detection technique is adopted. The energy-pooling collisions between Na (3P) and K (4P) are observed and cross sections are obtained.

•Feb 1, 1997•0 citations

The temperature dependence of the cross section for the energy pooling process Na(3P)+Na(3P)to Na(4D)+Na(3S)

Vlasta Horvatić, Mladen Movre, Cedomil Vadla

We report the measurements of the temperature dependence of the cross section 4D for the energy pooling process Na(3P)+Na(3P) Na(4D)+Na(3S). The latest two, as yet undisputed, results for 4D obtained by different authors at T = 597 K and T = 483 K suggest that this cross section decreases with increasing T , which contradicts the theory and other experiments on similar processes. To resolve this controversy and to examine the temperature trend of the cross section, we have measured the 4D in the temperature range 567-705 K, covering the high-temperature region that has not yet been investigated experimentally. To determine 4D we have excited sodium atoms in the quasistatic wing of the D1 line using a cw dye laser and measured the fluorescence intensity for the 4D 3P 3/2 transition, relative to the intensity of the optically thin quasistatic wing of the D2 line. The spatial distribution of the number density of the sodium atoms in the 3P 3/2 state and the sodium ground-state number density were measured too. The method used for the determination of the cross section is advantageous since it entirely circumvents the need to account for the radiation trapping of 3P level radiation, which was substantial under experimental conditions of the ground-state densities being 10 14 -10 16 cm -3 . The measurements of the cross section 4D in the investigated temperature range have shown that it increases as ~exp(- E / kT ). From the experiment we obtained E = (608±95) cm -1 , which is in excellent agreement with the energy defect (613 cm -1 ) for the considered process, and in fair agreement with the values which follow from recent theoretical calculations.

Journal of Physics B Atomic Molecular and Optical Physics•Oct 14, 1999•5 citations

Cross-section measurement for the energy-transfer collisions Na(3P)+Na(3P)→Na(5S,4D)+Na(3S)

M. Allegrini, Paola Bicchi, L. Moi

We report our measurements of the cross sections ${\ensuremath{\sigma}}_{5S}$ and ${\ensuremath{\sigma}}_{4D}$ for the electronic-energy-transfer process $\mathrm{Na}(3P)+\mathrm{Na}(3P)\ensuremath{\rightarrow}\mathrm{Na}(5S,4D)+\mathrm{Na}(3S)$. To obtain these cross sections we have measured the fluorescence intensity for the transitions $5S\ensuremath{\rightarrow}3P$, $4D\ensuremath{\rightarrow}3P$, and $3P\ensuremath{\rightarrow}3S$ in sodium vapor excited with a cw dye laser. The study of this electronic energy transfer is complicated and there is a large disagreement (\ensuremath{\gtrsim}${10}^{4}$) among reported measurements. We believe we have avoided most of the difficulties of previous experiments. Our results are ${\ensuremath{\sigma}}_{5S}=(2.0\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ ${\mathrm{cm}}^{2}$ and ${\ensuremath{\sigma}}_{4D}=(3.2\ifmmode\pm\else\textpm\fi{}1.1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ ${\mathrm{cm}}^{\ensuremath{-}2}$, and they are compared with the results of other experiments.

Physical Review A•Sep 1, 1983•59 citations

Ion formation in laser-irradiated sodium vapor

M. Allegrini, W. P. Garver, Vikram S. Kushawaha +1 more

The formation of ${\mathrm{Na}}^{+}$ and ${\mathrm{Na}}_{2}^{+}$ in laser-irradiated sodium vapor has been studied using a nitrogen-laser-pumped dye laser. The effects of irradiation by this pulsed laser are substantially different from those reported previously using a cw device, but otherwise identical experimental conditions. In contrast to the earlier experiments, in which ions were observed only when the cw laser was tuned to a $D$ line, relatively large "background" ion signals are observed at all excitation wavelengths, a result of multiphoton processes involving the ${\mathrm{Na}}_{2}$ component of the vapor. It is shown that the laser bandwidth and pulse duration are extremely important parameters; a wide bandwidth effectively magnifying the importance of the dimer component of the vapor and a short pulse duration minimizing the effects of interactions between excited atoms and molecules.

Physical Review A•Jul 1, 1983•19 citations

Energy-pooling collisions for K(4P)+Rb(5P) and Na(3P)+Rb(5P) heteronuclear systems

C. Gabbanini, Silvia Gozzini, G. Squadrito +2 more

The rate constants of the energy-pooling collisions in the Na-Rb and K-Rb vapor mixtures, resonantly excited by two cw dye lasers, have been measured relative to a known energy-pooling rate constant of a homonuclear reaction. To isolate the heteronuclear contribution in the fluorescence spectrum, a double-modulation technique has been adopted. The effective lifetimes of the excited levels that explicitly appear in the solution equation have been directly measured by using pulsed lasers. A discussion about the collision cross-section dependence on the energy defect involved in the energy-pooling collisions is reported.

Physical Review A•Jun 1, 1989•33 citations
The formation of Na (nl\mathrm{nl}nl) and Na2+\mathrm{Na}_{2}^{}{}_{}{}^{+}Na2​​+ in sodium vapor (\ensuremath{\sim}1013{10}^{13}1013 cm\ensuremath−3{\mathrm{cm}}^{\ensuremath{-}3}cm\ensuremath−3) irradiated by a single-frequency (20-MHz bandwidth) cw dye laser tuned to one of the DDD lines has been studied. The dependence of product signal on laser power density suggests that Na 3p3p3p-Na 3p3p3p energy pooling collisions are responsible for these species. Rate constants for specific reaction channels and temperature dependences of rate constants are also reported.
We have observed ion formation (both Na+{\mathrm{Na}}^{+}Na+ and Na2+{\mathrm{Na}}_{2}^{+}Na2+​) and radiation from high-lying Na states when low-density vapor (\ensuremath{\sim}1013{10}^{13}1013 ${\mathrm{cm}}^{\ensuremath{-}3}$) is irradiated with a cw dye laser tuned to one of the DDD lines. The Na+{\mathrm{Na}}^{+}Na+ ions probably result from photodissociation of Na2+{\mathrm{Na}}_{2}^{+}Na2+​ formed by $\mathrm{Na}(3p)\ensuremath{-}\mathrm{Na}(3p)$ associative ionization, while the high-lying radiating states are formed in energy-pooling reactions.
Two different atomic species, sodium and potassium, are resonantly excited in a ceel by a CW dye laser and a potassium lamp, respectively. The density of the excited Na (3P) atoms in the cell is measured directly using the absorption-equivalent-width technique on the lines of the diffuse series. To isolate the heteronuclear contribution in the fluorescence spectrum, a modulation detection technique is adopted. The energy-pooling collisions between Na (3P) and K (4P) are observed and cross sections are obtained.
We report the measurements of the temperature dependence of the cross section 4D for the energy pooling process Na(3P)+Na(3P) Na(4D)+Na(3S). The latest two, as yet undisputed, results for 4D obtained by different authors at T = 597 K and T = 483 K suggest that this cross section decreases with increasing T , which contradicts the theory and other experiments on similar processes. To resolve this controversy and to examine the temperature trend of the cross section, we have measured the 4D in the temperature range 567-705 K, covering the high-temperature region that has not yet been investigated experimentally. To determine 4D we have excited sodium atoms in the quasistatic wing of the D1 line using a cw dye laser and measured the fluorescence intensity for the 4D 3P 3/2 transition, relative to the intensity of the optically thin quasistatic wing of the D2 line. The spatial distribution of the number density of the sodium atoms in the 3P 3/2 state and the sodium ground-state number density were measured too. The method used for the determination of the cross section is advantageous since it entirely circumvents the need to account for the radiation trapping of 3P level radiation, which was substantial under experimental conditions of the ground-state densities being 10 14 -10 16 cm -3 . The measurements of the cross section 4D in the investigated temperature range have shown that it increases as ~exp(- E / kT ). From the experiment we obtained E = (608±95) cm -1 , which is in excellent agreement with the energy defect (613 cm -1 ) for the considered process, and in fair agreement with the values which follow from recent theoretical calculations.
We report our measurements of the cross sections ${\ensuremath{\sigma}}_{5S}$ and ${\ensuremath{\sigma}}_{4D}$ for the electronic-energy-transfer process $\mathrm{Na}(3P)+\mathrm{Na}(3P)\ensuremath{\rightarrow}\mathrm{Na}(5S,4D)+\mathrm{Na}(3S)$. To obtain these cross sections we have measured the fluorescence intensity for the transitions $5S\ensuremath{\rightarrow}3P$, $4D\ensuremath{\rightarrow}3P$, and $3P\ensuremath{\rightarrow}3S$ in sodium vapor excited with a cw dye laser. The study of this electronic energy transfer is complicated and there is a large disagreement (\ensuremath{\gtrsim}104{10}^{4}104) among reported measurements. We believe we have avoided most of the difficulties of previous experiments. Our results are ${\ensuremath{\sigma}}_{5S}=(2.0\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ cm2{\mathrm{cm}}^{2}cm2 and ${\ensuremath{\sigma}}_{4D}=(3.2\ifmmode\pm\else\textpm\fi{}1.1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ ${\mathrm{cm}}^{\ensuremath{-}2}$, and they are compared with the results of other experiments.
The formation of Na+{\mathrm{Na}}^{+}Na+ and Na2+{\mathrm{Na}}_{2}^{+}Na2+​ in laser-irradiated sodium vapor has been studied using a nitrogen-laser-pumped dye laser. The effects of irradiation by this pulsed laser are substantially different from those reported previously using a cw device, but otherwise identical experimental conditions. In contrast to the earlier experiments, in which ions were observed only when the cw laser was tuned to a DDD line, relatively large "background" ion signals are observed at all excitation wavelengths, a result of multiphoton processes involving the Na2{\mathrm{Na}}_{2}Na2​ component of the vapor. It is shown that the laser bandwidth and pulse duration are extremely important parameters; a wide bandwidth effectively magnifying the importance of the dimer component of the vapor and a short pulse duration minimizing the effects of interactions between excited atoms and molecules.
The rate constants of the energy-pooling collisions in the Na-Rb and K-Rb vapor mixtures, resonantly excited by two cw dye lasers, have been measured relative to a known energy-pooling rate constant of a homonuclear reaction. To isolate the heteronuclear contribution in the fluorescence spectrum, a double-modulation technique has been adopted. The effective lifetimes of the excited levels that explicitly appear in the solution equation have been directly measured by using pulsed lasers. A discussion about the collision cross-section dependence on the energy defect involved in the energy-pooling collisions is reported.