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 excitation transfer in high magnetic fields. III. Potential symmetry rules and correlation function in Na(3PJ2)−Na(3S122) collisions

J. C. Gay, Werner B. Schneider

Published Sep 1, 1979• 10 citations
Publisher

Abstract

An experimental study of excitation transfer between certain Zeeman sublevels of the $3^{2}P_{J}$ states in strong magnetic fields is reported for $\mathrm{Na}(3^{2}S_{\frac{1}{2}})\ensuremath{-}{\mathrm{Na}}^{*}(3^{2}P_{J})$ resonant collisions. A major decrease in the $M=\ensuremath{-}\frac{3}{2}\ensuremath{\rightarrow}M=\frac{3}{2}$ transfer rate is observed between 4 and 80 kG. Approximate calculations in the correlation-function framework are performed, and the experimental results and theoretical predictions for the field dependence are in good agreement. Some insights into the mechanisms of the collision process are deduced and the particularly important role of the electronic spin is emphasized. The importance of the symmetry properties of the interaction potential is also directly demonstrated.

DOI
10.1103/physreva.20.905

Related papers

Collisional excitation transfer in high magnetic fields. II. Correlation function of the interaction in H(6P13)−Hg(6S01) collisions

J. C. Gay, Werner B. Schneider

The authors report results of the experimental study of excitation transfer between Zeeman sublevels of the $6^{3}P_{1}$ state of an even isotope of mercury in magnetic fields up to 80 kG, obtained by monitoring the transition from sudden to partially adiabatic collisions. The results are shown to be in good agreement with theoretical evaluations based on a numerical solution of the relaxation problem or on a correlation-function description using a ${R}^{\ensuremath{-}3}$ dipole-dipole interaction.

Physical Review A•Sep 1, 1979•9 citations

Collisional excitation transfer in high magnetic fields. I. Theory

J. C. Gay, Werner B. Schneider

The effects of strong magnetic fields on thermal collisions in a vapor are reviewed. Semiclassical and quantum-mechanical symmetry properties of the relaxation matrix are established for resonant collisions between identical atoms and nonresonant collisions with a structureless partner. The variations with field strength of the transfer rates between Zeeman sublevels for ${R}^{\ensuremath{-}3}$ dipole-dipole interaction and ${R}^{\ensuremath{-}6}$ Van der Waals interaction are obtained with an exact semiclassical computation of the collision matrix. These are then compared with those predicted with an approximate formulation by means of the symmetrical correlation function for the potential.

Physical Review A•Sep 1, 1979•14 citations

Magnetic field dependence of cross sections for collisional disorientation of 6P122 cesium atoms

J. Guiry, L. Krause

The magnetic field dependence of the cross sections for the disorientation of $6^{2}P_{\frac{1}{2}}$ cesium atoms, induced in Cs-He collisions, has been studied using Zeeman scanning techniques. A Cs-He mixture, contained in a fluorescence cell which was located in a magnetic field variable from 0 to 10 kG, was irradiated with the circularly polarized 8943-\AA{} component of cesium resonance radiation in a direction parallel to the field, and the polarization of the resonance fluorescence was monitored in the backward direction in relation to the helium pressure and to the magnetic field strength. The cross sections, which are in good agreement with the results obtained previously at high and low magnetic fields, exhibit a variation with the magnetic field, which is in accordance with theoretical predictions.

Physical Review A•Dec 1, 1975•17 citations

Magnetic field dependence of cross sections for collisional disorientation of 6 $sup 2$P$sub 1$/$sub 2$ cesium atoms

J. Guiry, L. Krause

The magnetic field dependence of the cross sections for the disorientation of 6 $sup 2$P$sub 1$/$sub 2$ cesium atoms, induced in Cs-He collisions, has been studied using Zeeman scanning techniques. A Cs-He mixture, contained in a fluorescence cell which was located in a magnetic field variable from 0 to 10 kG, was irradiated with the circularly polarized 8943-A component of cesium resonance radiation in a direction parallel to the field, and the polarization of the resonance fluorescence was monitored in the backward direction in relation to the helium pressure and to the magnetic field strength. The cross sections, which are in good agreement with the results obtained previously at high and low magnetic fields, exhibit a variation with the magnetic field, which is in accordance with theoretical predictions. (AIP)

Physical Review A•Dec 1, 1975•0 citations

Low-temperature collisions of NH(X3Σ−) molecules with He atoms in a magnetic field: Anab initiostudy

Roman V. Krems, H. R. Sadeghpour, A. Dalgarno +3 more

Ab initio calculations of cross sections and rate constants for elastic scattering and Zeeman relaxation in collisions of $\mathrm{NH}(X{}^{3}{\ensuremath{\Sigma}}^{\ensuremath{-}})$ molecules with ${}^{3}\mathrm{He}$ atoms in a magnetic field are presented and the mechanism for Zeeman transitions in ground-state ${}^{3}\ensuremath{\Sigma}$ molecules is established. The potential surface for He-NH interaction is obtained using all-electron coupled-cluster calculations with single, double, and noniterative triple excitations in a basis set augmented by bond functions. The ratio of the rates for elastic energy transfer and Zeeman relaxation in NH-${}^{3}\mathrm{He}$ collisions exceeds ${10}^{5}$ at temperatures between $0.5$ and 1 K.

Physical Review A•Nov 12, 2003•72 citations

Sodium 3P fine-structure excitation transfer induced by collisions with rubidium and caesium atoms

Cedomil Vadla, Mladen Movre, Vlasta Horvatić

The cross sections for the excitation energy transfer in the collisional processes Na*(3P 1 2/)+M(nS 1 2/) to or from Na*(3p 3 2/)+m(Ns 3 2/), m being ground-state Rb (n=5) or Cs (n=6) atom, have been measured by laser fluorescence method. With either of the two sodium 3P fine-structure states optically excited, the intensity ratio of the sensitized to direct fluorescence was measured. The polarization effects due to partially polarized and anisotropic direct fluorescence were investigated. The measured cross sections (T=530 K) for the sodium 3P fine-structure excitation transfer induced by collisions with Rb are: sigma ( 1 / 2 to 3 / 2 )=170 AA 2 , with an overall accuracy of 20%. The corresponding values in the Cs case are: sigma ( 1 / 2 to 3 / 2 )=140 AA 2 , sigma ( 3 / 2 to 1 / 2 )=83 AA 2 . The theoretical calculations reveal the decisive role of the dipole-quadrupole interaction. The obtained values are in satisfactory agreement with the experiment only if both the dipole-dipole and dipole-quadrupole interactions are taken into account, while the calculations involving the dipole-dipole term alone yield the cross section values which are as much as one order of magnitude lower than the experimentally observed ones.

Journal of Physics B Atomic Molecular and Optical Physics•Oct 14, 1994•4 citations
An experimental study of excitation transfer between certain Zeeman sublevels of the 32PJ3^{2}P_{J}32PJ​ states in strong magnetic fields is reported for Na(32S12)\ensuremath−Na∗(32PJ)\mathrm{Na}(3^{2}S_{\frac{1}{2}})\ensuremath{-}{\mathrm{Na}}^{*}(3^{2}P_{J})Na(32S21​​)\ensuremath−Na∗(32PJ​) resonant collisions. A major decrease in the M=\ensuremath−32\ensuremath→M=32M=\ensuremath{-}\frac{3}{2}\ensuremath{\rightarrow}M=\frac{3}{2}M=\ensuremath−23​\ensuremath→M=23​ transfer rate is observed between 4 and 80 kG. Approximate calculations in the correlation-function framework are performed, and the experimental results and theoretical predictions for the field dependence are in good agreement. Some insights into the mechanisms of the collision process are deduced and the particularly important role of the electronic spin is emphasized. The importance of the symmetry properties of the interaction potential is also directly demonstrated.
The authors report results of the experimental study of excitation transfer between Zeeman sublevels of the 63P16^{3}P_{1}63P1​ state of an even isotope of mercury in magnetic fields up to 80 kG, obtained by monitoring the transition from sudden to partially adiabatic collisions. The results are shown to be in good agreement with theoretical evaluations based on a numerical solution of the relaxation problem or on a correlation-function description using a ${R}^{\ensuremath{-}3}$ dipole-dipole interaction.
The effects of strong magnetic fields on thermal collisions in a vapor are reviewed. Semiclassical and quantum-mechanical symmetry properties of the relaxation matrix are established for resonant collisions between identical atoms and nonresonant collisions with a structureless partner. The variations with field strength of the transfer rates between Zeeman sublevels for ${R}^{\ensuremath{-}3}$ dipole-dipole interaction and ${R}^{\ensuremath{-}6}$ Van der Waals interaction are obtained with an exact semiclassical computation of the collision matrix. These are then compared with those predicted with an approximate formulation by means of the symmetrical correlation function for the potential.
The magnetic field dependence of the cross sections for the disorientation of 62P126^{2}P_{\frac{1}{2}}62P21​​ cesium atoms, induced in Cs-He collisions, has been studied using Zeeman scanning techniques. A Cs-He mixture, contained in a fluorescence cell which was located in a magnetic field variable from 0 to 10 kG, was irradiated with the circularly polarized 8943-\AA{} component of cesium resonance radiation in a direction parallel to the field, and the polarization of the resonance fluorescence was monitored in the backward direction in relation to the helium pressure and to the magnetic field strength. The cross sections, which are in good agreement with the results obtained previously at high and low magnetic fields, exhibit a variation with the magnetic field, which is in accordance with theoretical predictions.
Magnetic field dependence of cross sections for collisional disorientation of 6 sup2sup 2sup2Psub1sub 1sub1/sub2sub 2sub2 cesium atoms
The magnetic field dependence of the cross sections for the disorientation of 6 sup2sup 2sup2Psub1sub 1sub1/sub2sub 2sub2 cesium atoms, induced in Cs-He collisions, has been studied using Zeeman scanning techniques. A Cs-He mixture, contained in a fluorescence cell which was located in a magnetic field variable from 0 to 10 kG, was irradiated with the circularly polarized 8943-A component of cesium resonance radiation in a direction parallel to the field, and the polarization of the resonance fluorescence was monitored in the backward direction in relation to the helium pressure and to the magnetic field strength. The cross sections, which are in good agreement with the results obtained previously at high and low magnetic fields, exhibit a variation with the magnetic field, which is in accordance with theoretical predictions. (AIP)
Ab initio calculations of cross sections and rate constants for elastic scattering and Zeeman relaxation in collisions of $\mathrm{NH}(X{}^{3}{\ensuremath{\Sigma}}^{\ensuremath{-}})$ molecules with 3He{}^{3}\mathrm{He}3He atoms in a magnetic field are presented and the mechanism for Zeeman transitions in ground-state ${}^{3}\ensuremath{\Sigma}$ molecules is established. The potential surface for He-NH interaction is obtained using all-electron coupled-cluster calculations with single, double, and noniterative triple excitations in a basis set augmented by bond functions. The ratio of the rates for elastic energy transfer and Zeeman relaxation in NH-3He{}^{3}\mathrm{He}3He collisions exceeds 105{10}^{5}105 at temperatures between 0.50.50.5 and 1 K.
The cross sections for the excitation energy transfer in the collisional processes Na*(3P 1 2/)+M(nS 1 2/) to or from Na*(3p 3 2/)+m(Ns 3 2/), m being ground-state Rb (n=5) or Cs (n=6) atom, have been measured by laser fluorescence method. With either of the two sodium 3P fine-structure states optically excited, the intensity ratio of the sensitized to direct fluorescence was measured. The polarization effects due to partially polarized and anisotropic direct fluorescence were investigated. The measured cross sections (T=530 K) for the sodium 3P fine-structure excitation transfer induced by collisions with Rb are: sigma ( 1 / 2 to 3 / 2 )=170 AA 2 , with an overall accuracy of 20%. The corresponding values in the Cs case are: sigma ( 1 / 2 to 3 / 2 )=140 AA 2 , sigma ( 3 / 2 to 1 / 2 )=83 AA 2 . The theoretical calculations reveal the decisive role of the dipole-quadrupole interaction. The obtained values are in satisfactory agreement with the experiment only if both the dipole-dipole and dipole-quadrupole interactions are taken into account, while the calculations involving the dipole-dipole term alone yield the cross section values which are as much as one order of magnitude lower than the experimentally observed ones.