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 Letters

Measurement of Large Cross Sections for Laser-Induced Collisions

William R. Green, Jacques Lukasik, John R. Willison, M. D. Wright, J. F. Young, Stephen E. Harris

Published Apr 9, 1979• 69 citations
Publisher

Abstract

We report measurements of cross sections greater than ${10}^{\ensuremath{-}13}$ ${\mathrm{cm}}^{2}$ for laser-induced inelastic collisions between Sr and Ca. We describe an experimental system which produces such large cross sections and which greatly facilitates the study of laser-induced collisions through its ability to reduce noise from other collisional processes.

DOI
10.1103/physrevlett.42.970

Related papers

Observation of laser-induced inelastic collisions

R. W. Falcone, William R. Green, J. C. White +2 more

We describe two new experiments which demonstrate laser-induced inelastic collisions. Energy was stored in the Sr $5p^{1}P^{o}$ state and selectively transferred both to the Ca $4{p}^{2}^{1}S$ and $5d^{1}D$ states. The collision cross sections maximized at the interatomic wavelengths of 4977 and 4711 \AA{}, respectively, and had a half-power width of about 14 ${\mathrm{cm}}^{\ensuremath{-}1}$.

Physical Review A•Mar 1, 1977•136 citations

Laser-induced charge-transfer collisions of calcium ions with strontium atoms

M. D. Wright, D. M. O'Brien, J. F. Young +1 more

Experimental studies of two laser-induced charge-transfer reactions in Ca and Sr are presented. In both reactions, a Ca ion collides with an Sr neutral in the presence of a laser field to produce a Ca neutral and an excited Sr ion. The two reactions differ in the final level of the ${\mathrm{Sr}}^{+}$ species. The collision cross sections associated with these reactions are studied as functions of applied laser frequency and power density. The largest cross section induced is equal to ${10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$, obtained at a power density of 2\ifmmode\times\else\texttimes\fi{}${10}^{9}$ W/${\mathrm{cm}}^{2}$. Differences in experimental results associated with the two reactions are explained qualitatively by an examination of the potential curves of the Ca${\mathrm{Sr}}^{+}$ quasimolecule.

Physical Review A•Oct 1, 1981•6 citations

Inelastic cross sections in Cs(nDJ2)+Cs(6S122) collisions

A. C. Tam, T. Yabuzaki, Stephen M. Curry +2 more

The inelastic collisional cross sections of the $\mathrm{nD}$ states of Cs are measured by the technique of selective laser excitation and observation of collision-induced fluorescence. The cross sections (in units of ${10}^{\ensuremath{-}14}$ ${\mathrm{cm}}^{2}$) for the fine-structure-changing collisions [i.e., $\mathrm{Cs}(n^{2}D_{\frac{3}{2}})+\mathrm{Cs}(6^{2}S_{\frac{1}{2}})\ensuremath{\rightarrow}\mathrm{Cs}(n^{2}D_{\frac{5}{2}})+\mathrm{Cs}(6^{2}S_{\frac{1}{2}})$] for $n$ being 6-10 are 2.7\ifmmode\pm\else\textpm\fi{}0.5, 3.7\ifmmode\pm\else\textpm\fi{}0.7, 8.6\ifmmode\pm\else\textpm\fi{}1.7, 18.4\ifmmode\pm\else\textpm\fi{}3.7, and 29.8\ifmmode\pm\else\textpm\fi{}6.0, respectively. The cross sections (in ${10}^{\ensuremath{-}14}$ ${\mathrm{cm}}^{2}$) for excitation transfer out of the $\mathrm{nD}$ doublet [i.e., $\mathrm{Cs}(n^{2}D_{\frac{5}{2}})+\mathrm{Cs}(6^{2}S_{\frac{1}{2}})\ensuremath{\rightarrow}\mathrm{states}\mathrm{other}\mathrm{than} \mathrm{Cs}(\mathrm{nD})$] for $n$ being 6-10 are 1.1\ifmmode\pm\else\textpm\fi{}0.6, 5.3\ifmmode\pm\else\textpm\fi{}1.5, 3.6\ifmmode\pm\else\textpm\fi{}1.5, 6.3\ifmmode\pm\else\textpm\fi{}2.3, and 15.5\ifmmode\pm\else\textpm\fi{}4.0, respectively. The fine-structure-changing cross sections are found to be nearly equal to the geometrical cross section $\ensuremath{\pi}{n}^{*4}{a}_{0}^{2}$ for all the $\mathrm{nD}$ states studied, except $6D$, whose fine-structure-changing cross section is unusually large.

Physical Review A•Jun 1, 1978•29 citations

Theory of laser-induced inelastic collisions

S. Geltman

A theory of laser-induced inelastic collisions is presented, containing atomic selection rules and specific intensity and velocity dependences. It is applied to the case of the process Sr(5p 1 P 0 )+Ca(4s 2 1 S)+h(cross) omega (6408.6 AA) to Sr(5s 2 1 S)+Ca(4d 1 D), for which the intensity and wavelength dependence of the cross section is evaluated.

Journal of Physics B Atomic and Molecular Physics•Dec 21, 1976•50 citations

Observation of a laser-induced dipole–quadrupole collision

William R. Green, M. D. Wright, Jacques Lukasik +2 more

Experimental observation of a laser-induced dipole-quadrupole collision between Sr and Ca is reported. The laser-induced collision cross section peaks at an applied photon energy equal to the energy defect of the initial and final states of the infinitely separated atoms. A cross section of 3 x 10(-14) cm(2) was induced at a laser-power density of 7 x 10(9) W/cm(2); the linewidth was 20 cm(-1).

Optics Letters•Sep 1, 1979•32 citations

Cross sections for sodium fine-structure transitions induced by collision with caesium atoms

Martin A. Harris, E L Lewis

Cross sections for the process Na(3 2 P 1 2/)+ Delta E to or from Na(3 2 P 3 2/) induced by inelastic collisions with ground-state caesium atoms have been measured and the results are discussed with reference to resonant and rare-gas-induced cross sections and non-adiabatic effects.

Journal of Physics B Atomic and Molecular Physics•Sep 4, 1982•6 citations
We report measurements of cross sections greater than 10\ensuremath−13{10}^{\ensuremath{-}13}10\ensuremath−13 cm2{\mathrm{cm}}^{2}cm2 for laser-induced inelastic collisions between Sr and Ca. We describe an experimental system which produces such large cross sections and which greatly facilitates the study of laser-induced collisions through its ability to reduce noise from other collisional processes.
We describe two new experiments which demonstrate laser-induced inelastic collisions. Energy was stored in the Sr 5p1Po5p^{1}P^{o}5p1Po state and selectively transferred both to the Ca $4{p}^{2}^{1}S$ and 5d1D5d^{1}D5d1D states. The collision cross sections maximized at the interatomic wavelengths of 4977 and 4711 \AA{}, respectively, and had a half-power width of about 14 ${\mathrm{cm}}^{\ensuremath{-}1}$.
Experimental studies of two laser-induced charge-transfer reactions in Ca and Sr are presented. In both reactions, a Ca ion collides with an Sr neutral in the presence of a laser field to produce a Ca neutral and an excited Sr ion. The two reactions differ in the final level of the Sr+{\mathrm{Sr}}^{+}Sr+ species. The collision cross sections associated with these reactions are studied as functions of applied laser frequency and power density. The largest cross section induced is equal to ${10}^{\ensuremath{-}16}$ cm2{\mathrm{cm}}^{2}cm2, obtained at a power density of 2\ifmmode\times\else\texttimes\fi{}109{10}^{9}109 W/cm2{\mathrm{cm}}^{2}cm2. Differences in experimental results associated with the two reactions are explained qualitatively by an examination of the potential curves of the CaSr+{\mathrm{Sr}}^{+}Sr+ quasimolecule.
The inelastic collisional cross sections of the nD\mathrm{nD}nD states of Cs are measured by the technique of selective laser excitation and observation of collision-induced fluorescence. The cross sections (in units of ${10}^{\ensuremath{-}14}$ cm2{\mathrm{cm}}^{2}cm2) for the fine-structure-changing collisions [i.e., $\mathrm{Cs}(n^{2}D_{\frac{3}{2}})+\mathrm{Cs}(6^{2}S_{\frac{1}{2}})\ensuremath{\rightarrow}\mathrm{Cs}(n^{2}D_{\frac{5}{2}})+\mathrm{Cs}(6^{2}S_{\frac{1}{2}})$] for nnn being 6-10 are 2.7\ifmmode\pm\else\textpm\fi{}0.5, 3.7\ifmmode\pm\else\textpm\fi{}0.7, 8.6\ifmmode\pm\else\textpm\fi{}1.7, 18.4\ifmmode\pm\else\textpm\fi{}3.7, and 29.8\ifmmode\pm\else\textpm\fi{}6.0, respectively. The cross sections (in ${10}^{\ensuremath{-}14}$ cm2{\mathrm{cm}}^{2}cm2) for excitation transfer out of the nD\mathrm{nD}nD doublet [i.e., $\mathrm{Cs}(n^{2}D_{\frac{5}{2}})+\mathrm{Cs}(6^{2}S_{\frac{1}{2}})\ensuremath{\rightarrow}\mathrm{states}\mathrm{other}\mathrm{than} \mathrm{Cs}(\mathrm{nD})$] for nnn being 6-10 are 1.1\ifmmode\pm\else\textpm\fi{}0.6, 5.3\ifmmode\pm\else\textpm\fi{}1.5, 3.6\ifmmode\pm\else\textpm\fi{}1.5, 6.3\ifmmode\pm\else\textpm\fi{}2.3, and 15.5\ifmmode\pm\else\textpm\fi{}4.0, respectively. The fine-structure-changing cross sections are found to be nearly equal to the geometrical cross section $\ensuremath{\pi}{n}^{*4}{a}_{0}^{2}$ for all the nD\mathrm{nD}nD states studied, except 6D6D6D, whose fine-structure-changing cross section is unusually large.