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

Chemical Physics

Time-dependent study of the dynamics of the collision-induced intramultiplet mixing of Ca(4s4p(3P )) by helium at 750 K following pulsed dye-laser generation of Ca(4s4p(3P1))

Fernando Beitia, Fernando Castaño, Marı́a N. Sánchez Rayo, David Husain

Published Oct 1, 1992• 19 citations
Publisher
DOI
10.1016/0301-0104(92)87025-5

Related papers

Laser gain on the 4p3d 3F-4s3d 3D transitions of Ca following optical excitation of the 4s4p 3P1 state

Muhammad Arshad Khan, M.A. Gondal, M. H. Rais

Optics Communications•Feb 1, 1996•3 citations

Collisional excitation of 4p /sup 2/P states of Ca/sup +/ following pulsed-laser pumping of the 4s/sup 2/ /sup 1/S/sub 0/-4s4p /sup 3/P/sub 1/ transition of Ca

Muhammad Arshad Khan, M.A. Gondal, M. H. Rais

European Quantum Electronics Conference (EQEC)•Aug 24, 2005•0 citations

State-resolved fine-structure transitions in collisions of Ca 4s4p3PJ0with H2and D2molecules

H.‐J. Yuh, Paul J. Dagdigian

An optical pumping state-selection technique is employed for the measurement of intramultiplet mixing cross sections involving specified spin-orbit states of calcium 4s4p 3PJ0 atoms in collisions with H2 and D2. As was previously found for helium collisions, the J=2 to J'=1 cross sections are found to be the largest of the three possible downward transitions. However, differences in magnitude between the various J to J' cross sections are smaller than for helium. Moreover, the cross sections for the molecular targets are two to three times larger than for the same transitions with helium as the scattering partner. These differences are discussed in terms of the expected dynamics of fine-structure-changing transitions of 3P atoms with atomic and molecular scattering partners.

Journal of Physics B Atomic and Molecular Physics•Nov 14, 1984•7 citations

Energy pooling in an equilibrium-coupled system between Ca[4s3d(1D2)] and Mg[3s3p(3P j )] atoms following pulsed dye-laser excitation

David Husain, Gareth O. Roberts

We present a kinetic study of energy pooling in the equilibrium-coupled system: Ca[4s3d(1D2)]+ Mg[3s2(1S0)]⇌ Ca[4s2(1S0)]+ Mg[3s3p(3PJ)] following pulsed dye-laser excitation of both Mg(3PJ) and Ca(1D2) atoms at λ= 457.1 nm. [Mg(3P1)â†� Mg(1S0)] and λ= 457.5 nm [Ca(1D2)â†� Ca(1S0)] in the presence of helium across the temperature range 800–1100 K. Quantitative characterisation of decay profiles for Mg(3PJ) and Ca(1D2) by time-resolved emission measurements at the above wavelengths using boxcar integration indicates the effectively instantaneous establishment and maintenance of the near-resonant equilibrium under all conditions of temperature and pressure via the observed equality in the first-order decay coefficients for removal of both states. Energy pooling into some 16 higher-lying states of magnesium and calcium, including atomic levels close to the energetically accessible limit, were observed and their temporal behaviour characterised. With the exceptions of Mg[3s4s(3S1)] and Ca[4s4p(1P1)] atoms, all these pooled states exhibited first-order kinetic behaviour. Measured first-order decay coefficients for these pooled states were found to be always twice those of the energy store states, indicating their production via collisions involving the metastable states Mg(3PJ), Ca(1D2) and possibly Ca(3PJ). Initial relative populations of energy-pooled states were estimated in all cases and found to lie in the range 10–4–10–6, thus constituting a small ‘bleed-off’ from the and Ca(1D2) energy stores without disturbing the observed first-order decay of these two states in the equilibrium-coupled system.

Journal of the Chemical Society Faraday Transactions 2 Molecular and Chemical Physics•Jan 1, 1988•2 citations

Excitation transfer between excited levels of He (n = 3, 4) by dye laser pumping

K. Fukuda, S. Oku, Naoki Yasumaru

peac•Jan 1, 1979•0 citations

Energy pooling from Ca[4s4p(3 P J )] and Ca[4s3d(1 D 2)] studied by time-resolved atomic emission following pulsed dye-laser excitation

David Husain, Gareth O. Roberts

Two separate series of investigations have been carried out on the optically metastable states Ca[4s4p(3PJ)] and Ca[4s3d(1D2)], generated by pulsed dye-laser excitation at λ= 657.3 nm {Ca[4s4p(3P1)]â†� Ca[4s2(1S0)]} and λ= 457.5 nm {Ca[4s3d(1D2)]â†� Ca[4s2(1S0)]}, with particular emphasis on energy pooling. The kinetic behaviour of these two states has been characterised in detail across a wide range of temperature and pressure by time-resolved atomic emission measurements at the resonance wavelengths. In the case of Ca[4s3d(1D2)] these represent the first time-resolved measurements on this atomic state, yielding a mean radiative lifetime for emission to all lower states of τe= 1.71 ± 0.03 ms, in accord with time-of-flight measurements in atomic beams. The measured temperature dependence of the diffusion coefficient D12[Ca(4 1D2)–He], when expressed in the form D12∝Tn, yielded n= 1.77 ± 0.08. Further, the rate constant for the collisional quenching of Ca(4 1D2) by Ca(4 1S0) itself is estimated to be kCa=(4 ± 3)× 10–14 cm3 atom–1 s–1, in sensible accord with similar data for the quenching of Ca(4 3PJ) by the ground-state calcium atom. Energy pooling between Ca(4 3PJ)+ Ca(4 3PJ) is shown to give rise directly to Ca[4s4p(1P1)] and Ca[4s3d(1D2)]. Energy pooling between Ca(4 1D2)+ Ca(4 1D2) is shown to yield 22 electronic states, each of whose kinetic behaviour was characterised quantitatively from the relevant atomic emission profiles, including measurement of relative atomic yields.

Journal of the Chemical Society Faraday Transactions 2 Molecular and Chemical Physics•Jan 1, 1986•37 citations
An optical pumping state-selection technique is employed for the measurement of intramultiplet mixing cross sections involving specified spin-orbit states of calcium 4s4p 3PJ0 atoms in collisions with H2 and D2. As was previously found for helium collisions, the J=2 to J'=1 cross sections are found to be the largest of the three possible downward transitions. However, differences in magnitude between the various J to J' cross sections are smaller than for helium. Moreover, the cross sections for the molecular targets are two to three times larger than for the same transitions with helium as the scattering partner. These differences are discussed in terms of the expected dynamics of fine-structure-changing transitions of 3P atoms with atomic and molecular scattering partners.
We present a kinetic study of energy pooling in the equilibrium-coupled system: Ca[4s3d(1D2)]+ Mg[3s2(1S0)]⇌ Ca[4s2(1S0)]+ Mg[3s3p(3PJ)] following pulsed dye-laser excitation of both Mg(3PJ) and Ca(1D2) atoms at λ= 457.1 nm. [Mg(3P1)â†� Mg(1S0)] and λ= 457.5 nm [Ca(1D2)â†� Ca(1S0)] in the presence of helium across the temperature range 800–1100 K. Quantitative characterisation of decay profiles for Mg(3PJ) and Ca(1D2) by time-resolved emission measurements at the above wavelengths using boxcar integration indicates the effectively instantaneous establishment and maintenance of the near-resonant equilibrium under all conditions of temperature and pressure via the observed equality in the first-order decay coefficients for removal of both states. Energy pooling into some 16 higher-lying states of magnesium and calcium, including atomic levels close to the energetically accessible limit, were observed and their temporal behaviour characterised. With the exceptions of Mg[3s4s(3S1)] and Ca[4s4p(1P1)] atoms, all these pooled states exhibited first-order kinetic behaviour. Measured first-order decay coefficients for these pooled states were found to be always twice those of the energy store states, indicating their production via collisions involving the metastable states Mg(3PJ), Ca(1D2) and possibly Ca(3PJ). Initial relative populations of energy-pooled states were estimated in all cases and found to lie in the range 10–4–10–6, thus constituting a small ‘bleed-off’ from the and Ca(1D2) energy stores without disturbing the observed first-order decay of these two states in the equilibrium-coupled system.
Two separate series of investigations have been carried out on the optically metastable states Ca[4s4p(3PJ)] and Ca[4s3d(1D2)], generated by pulsed dye-laser excitation at λ= 657.3 nm {Ca[4s4p(3P1)]â†� Ca[4s2(1S0)]} and λ= 457.5 nm {Ca[4s3d(1D2)]â†� Ca[4s2(1S0)]}, with particular emphasis on energy pooling. The kinetic behaviour of these two states has been characterised in detail across a wide range of temperature and pressure by time-resolved atomic emission measurements at the resonance wavelengths. In the case of Ca[4s3d(1D2)] these represent the first time-resolved measurements on this atomic state, yielding a mean radiative lifetime for emission to all lower states of τe= 1.71 ± 0.03 ms, in accord with time-of-flight measurements in atomic beams. The measured temperature dependence of the diffusion coefficient D12[Ca(4 1D2)–He], when expressed in the form D12∝Tn, yielded n= 1.77 ± 0.08. Further, the rate constant for the collisional quenching of Ca(4 1D2) by Ca(4 1S0) itself is estimated to be kCa=(4 ± 3)× 10–14 cm3 atom–1 s–1, in sensible accord with similar data for the quenching of Ca(4 3PJ) by the ground-state calcium atom. Energy pooling between Ca(4 3PJ)+ Ca(4 3PJ) is shown to give rise directly to Ca[4s4p(1P1)] and Ca[4s3d(1D2)]. Energy pooling between Ca(4 1D2)+ Ca(4 1D2) is shown to yield 22 electronic states, each of whose kinetic behaviour was characterised quantitatively from the relevant atomic emission profiles, including measurement of relative atomic yields.