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

Coincident Photon Coherence Analysis of the Mercury 6S01−6P13−6S01 Excitation/Deexcitation Process in Terms of Spin-Orbit Effects

Ali Zaidi, Ian A. McGregor, Hans Kleinpoppen

Published Oct 6, 1980• 35 citations
Publisher

Abstract

The electron-photon delayed-coincidence technique was used to measure the coincident photon radiation for the $6^{1}S_{0}\ensuremath{\rightarrow}6^{3}P_{1}\ensuremath{\rightarrow}6^{1}S_{0}$ process of mercury by electron impact. This process, which is found to be partially coherent, has been analyzed with a new parametrization which takes into account spin-orbit coupling.

DOI
10.1103/physrevlett.45.1168

Related papers

Coincident Photon Coherence Analysis of the Mercury 6S01−6P13−6S01 Excitation/DEExcitation Process in Terms of Spinorbit Effects.

Ali Zaidi, Ian A. McGregor, Hans Kleinpoppen

On page 1169, the normalized Stokes param- eters in Table I have been incorrectly quoted.In the first line (footnote a), the given values should be changed to P, = -0.31+ 0.05, P, =0.21+0. 06,and P, = 0.14+ 0.05.In the remaining lines (foot- notes b), each value of P"P"and P, should be giveQ the opposite sign.This change ln slgQ results in different limits for X in Table II, page 1170.The existing values of &0.71, &0.56, &0.63, and &0.56 should be replaced by &0.29, &0.43, &0.37, and &0.43, respectively.

Physical Review Letters•Dec 22, 1980•4 citations

Electron-Photon Coincidence Studies in Collisions of Polarized Electrons with Mercury Atoms

A. Wolcke, Johannes Goeke, G F Hanne +4 more

Electron-photon coincidences with initially polarized electrons have been measured for the first time. Results for linear and circular polarization components of the 254-nm line (Hg $6^{3}P_{1}\ensuremath{-}6^{1}S_{0}$ transition) are presented as a function of electron energy for electrons which are scattered inelastically ($6^{3}P_{1}$ excitation) in the forward direction. The analysis of these polarization components allows one to determine the role of spin-dependent interactions during collision as well as to determine the relative phase of the two scattering amplitudes involved.

Physical Review Letters•Mar 26, 1984•29 citations

Correlation of Photons in Cascade and the Coherence Time of the 6P13 State of Mercury

Gilbert H. Nussbaum, F. M. Pipkin

We have observed directly the time correlation between successively emitted photons in the $7^{3}S_{1}\ensuremath{-}6^{3}P_{1}\ensuremath{-}6^{1}S_{0}$ cascade of atomic mercury, and have deduced from it direct measurements of both the natural lifetime of the $6^{3}P_{1}$ state and the dependence of the mean correlation time (coherence time) on the density of the mercury vapor surrounding the primary radiation region. The density-dependent coherence time constitutes a direct observation of the imprisonment of resonance radiation and provides an experimental confirmation of the theory describing this phenomenon.

Physical Review Letters•Nov 6, 1967•40 citations

6P13−6P03 Excitation Transfer in Mercury, Induced in Collisions with N2 Molecules

John M. Pitre, K. Hammond, L. Krause

The cross section for the transition $6^{3}P_{0}\ensuremath{\rightarrow}6^{3}P_{1}$ in mercury, induced in collisions with ${\mathrm{N}}_{2}$ molecules, has been determined by the method of delayed coincidences. The Hg $^{3}P_{1}$ state was excited by pulses of 2537-\AA{} Hg resonance radiation and the decay of the long-lived 2537-\AA{} afterglow was studied in relation to ${\mathrm{N}}_{2}$ pressure. The resulting cross section ${Q}_{12}(^{3}P_{0}\ensuremath{\rightarrow}^{3}P_{1})=4.18\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ ${\mathrm{\AA{}}}^{2}$ was found to be good agreement with the prediction of the principle of detailed balancing when compared with the cross section ${Q}_{21}(^{3}P_{1}\ensuremath{\rightarrow}^{3}P_{0})$. It was also found that, within the sensitivity of the method, collisions with ${\mathrm{N}}_{2}$ molecules do not quench $^{3}P_{1}$ or $^{3}P_{0}$ Hg atoms to the ground state.

Physical Review A•Dec 1, 1972•39 citations

A stepwise electron-photon coincidence experiment on the 61P1 state of mercury

Andrew James Murray

A new type of electron/photon coincidence experiment is presented which utilises a laser -electron stepwise excitation technique to prepare atoms in an excited state. An electron collision initially excites an atom from the ground state to an intermediate state. Following this electron excitation process, coherent single mode laser radiation further excites the atom to an upper state, from which the fluorescence is observed. The nature of the laser excitation transfers both amplitude and phase information about the electron excited state to the upper excited state in a coherent way. This information is extracted from the upper state fluorescence by analysis of the fluorescence polarization in coincidence with the electron scattered from the atom for particular polarizations of the laser radiation. The coincidence technique allows an identically prepared sub -ensemble of excited atoms to be selected for measurement. The electron excited state studied was the 61131 state of mercury, excited by a beam of unpolarized electrons at an impact energy of 16 eV. The mercury atomic beam was isotopically selected following electron excitation using the narrow bandwidth of the laser radiation. Excitation from the electron excited 61P1 state was via 579 nm laser radiation to the 61D2 state and fluorescence was monitored from this state to the 63P1 state via a 313 nm transition. Stokes parameters were measured for two different laser polarization angles, since this allowed a complete set of collision parameters to be deduced for a single experimental geometry. Results for three different scattering angles at this energy are presented. The laser excitation process was modelled in both the weak and the strong laser excitation regimes. A perturbation approach developed to model single photon laser excitation allowed the collision parameters to be extracted from the measured coincidence Stokes parameters analytically, whereas a Quantum Electrodynamic model allowed high laser intensity effects on the coincidence signal to be explored theoretically. The Quantum Electrodynamic model indicated that the weak excitation model could be used to extract the collision parameters from the Stokes parameters at the laser intensities used in the experiment. Effects due to variation of the laser intensity were predicted from the Quantum Electrodynamic model and experiments conducted to test these predictions are presented. Collision parameters deduced from the measured stepwise coincidence Stokes parameters following optimization of the experimental conditions are presented. These parameters are compared qualitatively with existing data from heavy atomic systems and with a theoretical model based upon the Distorted Wave Born Approximation. Similarities between the experimental data are found, however significant discrepancies are noted between the parameters obtained here and with the predictions of the theoretical model.

•Jan 1, 1989•0 citations

Electron-Photon Coincidence Technique for Atomic Collisions

Mevlüt Doğan, Hüseyin Ali Yalım

A brief review is given on development of electron-photon coincidence studies from electron impact of atoms. The theory of electron-photon correlations is outlined in detail in terms of cross sections of excited atoms and excited state charge clouds. The state of a target atom is determined by the various orientation and alignment parameters and the multipole moments of the excited atom. General considerations, such as coherence effects in impact excitation, the influence of fine and hyperfine structures in correlations are taken into account. The relationship between scattering amplitudes (including their phases) and target parameters is worked out for singlet and doublet transitions.

Afyon Kocatepe Üniversitesi Fen Ve Mühendislik Bilimleri Dergisi•Jun 1, 2003•0 citations
The electron-photon delayed-coincidence technique was used to measure the coincident photon radiation for the 61S0\ensuremath→63P1\ensuremath→61S06^{1}S_{0}\ensuremath{\rightarrow}6^{3}P_{1}\ensuremath{\rightarrow}6^{1}S_{0}61S0​\ensuremath→63P1​\ensuremath→61S0​ process of mercury by electron impact. This process, which is found to be partially coherent, has been analyzed with a new parametrization which takes into account spin-orbit coupling.
On page 1169, the normalized Stokes param- eters in Table I have been incorrectly quoted.In the first line (footnote a), the given values should be changed to P, = -0.31+ 0.05, P, =0.21+0. 06,and P, = 0.14+ 0.05.In the remaining lines (foot- notes b), each value of P"P"and P, should be giveQ the opposite sign.This change ln slgQ results in different limits for X in Table II, page 1170.The existing values of &0.71, &0.56, &0.63, and &0.56 should be replaced by &0.29, &0.43, &0.37, and &0.43, respectively.
Electron-photon coincidences with initially polarized electrons have been measured for the first time. Results for linear and circular polarization components of the 254-nm line (Hg $6^{3}P_{1}\ensuremath{-}6^{1}S_{0}$ transition) are presented as a function of electron energy for electrons which are scattered inelastically (63P16^{3}P_{1}63P1​ excitation) in the forward direction. The analysis of these polarization components allows one to determine the role of spin-dependent interactions during collision as well as to determine the relative phase of the two scattering amplitudes involved.
We have observed directly the time correlation between successively emitted photons in the $7^{3}S_{1}\ensuremath{-}6^{3}P_{1}\ensuremath{-}6^{1}S_{0}$ cascade of atomic mercury, and have deduced from it direct measurements of both the natural lifetime of the 63P16^{3}P_{1}63P1​ state and the dependence of the mean correlation time (coherence time) on the density of the mercury vapor surrounding the primary radiation region. The density-dependent coherence time constitutes a direct observation of the imprisonment of resonance radiation and provides an experimental confirmation of the theory describing this phenomenon.
The cross section for the transition $6^{3}P_{0}\ensuremath{\rightarrow}6^{3}P_{1}$ in mercury, induced in collisions with N2{\mathrm{N}}_{2}N2​ molecules, has been determined by the method of delayed coincidences. The Hg 3P1^{3}P_{1}3P1​ state was excited by pulses of 2537-\AA{} Hg resonance radiation and the decay of the long-lived 2537-\AA{} afterglow was studied in relation to N2{\mathrm{N}}_{2}N2​ pressure. The resulting cross section ${Q}_{12}(^{3}P_{0}\ensuremath{\rightarrow}^{3}P_{1})=4.18\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ A˚2{\mathrm{\AA{}}}^{2}A˚2 was found to be good agreement with the prediction of the principle of detailed balancing when compared with the cross section ${Q}_{21}(^{3}P_{1}\ensuremath{\rightarrow}^{3}P_{0})$. It was also found that, within the sensitivity of the method, collisions with N2{\mathrm{N}}_{2}N2​ molecules do not quench 3P1^{3}P_{1}3P1​ or 3P0^{3}P_{0}3P0​ Hg atoms to the ground state.
A new type of electron/photon coincidence experiment is presented which utilises a laser -electron stepwise excitation technique to prepare atoms in an excited state. An electron collision initially excites an atom from the ground state to an intermediate state. Following this electron excitation process, coherent single mode laser radiation further excites the atom to an upper state, from which the fluorescence is observed. The nature of the laser excitation transfers both amplitude and phase information about the electron excited state to the upper excited state in a coherent way. This information is extracted from the upper state fluorescence by analysis of the fluorescence polarization in coincidence with the electron scattered from the atom for particular polarizations of the laser radiation. The coincidence technique allows an identically prepared sub -ensemble of excited atoms to be selected for measurement. The electron excited state studied was the 61131 state of mercury, excited by a beam of unpolarized electrons at an impact energy of 16 eV. The mercury atomic beam was isotopically selected following electron excitation using the narrow bandwidth of the laser radiation. Excitation from the electron excited 61P1 state was via 579 nm laser radiation to the 61D2 state and fluorescence was monitored from this state to the 63P1 state via a 313 nm transition. Stokes parameters were measured for two different laser polarization angles, since this allowed a complete set of collision parameters to be deduced for a single experimental geometry. Results for three different scattering angles at this energy are presented. The laser excitation process was modelled in both the weak and the strong laser excitation regimes. A perturbation approach developed to model single photon laser excitation allowed the collision parameters to be extracted from the measured coincidence Stokes parameters analytically, whereas a Quantum Electrodynamic model allowed high laser intensity effects on the coincidence signal to be explored theoretically. The Quantum Electrodynamic model indicated that the weak excitation model could be used to extract the collision parameters from the Stokes parameters at the laser intensities used in the experiment. Effects due to variation of the laser intensity were predicted from the Quantum Electrodynamic model and experiments conducted to test these predictions are presented. Collision parameters deduced from the measured stepwise coincidence Stokes parameters following optimization of the experimental conditions are presented. These parameters are compared qualitatively with existing data from heavy atomic systems and with a theoretical model based upon the Distorted Wave Born Approximation. Similarities between the experimental data are found, however significant discrepancies are noted between the parameters obtained here and with the predictions of the theoretical model.
A brief review is given on development of electron-photon coincidence studies from electron impact of atoms. The theory of electron-photon correlations is outlined in detail in terms of cross sections of excited atoms and excited state charge clouds. The state of a target atom is determined by the various orientation and alignment parameters and the multipole moments of the excited atom. General considerations, such as coherence effects in impact excitation, the influence of fine and hyperfine structures in correlations are taken into account. The relationship between scattering amplitudes (including their phases) and target parameters is worked out for singlet and doublet transitions.