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

Journal of Physics Conference Series

Formation of molecular ion LiHe+by radiative association of metastable helium He(23P) with lithium ions

Martina Zámečníková, Lucie D. Augustovičová, Wolfgang P Kraemer, Pavel Soldán

Published Sep 7, 2015• 0 citations
Publisher

Abstract

Radiative association of metastable helium He(2 3 P) with lithium ions is theoretically investigated on the triplet-sigma manifold. Cross-sections and the corresponding rate coefficients for spontaneous and stimulated processes are calculated. Results are compared to other radiative and non-radiative processes in collisions of metastable helium with lithium ions.

DOI
10.1088/1742-6596/635/2/022038

Related papers

Spin exchange cross sections for collisions of metastable helium atoms with lithium atoms in the ground state

Victor A. Kartoshkin

The spin exchange and chemi-ionization cross sections for the metastable helium atom-lithium atom in the ground state system have been calculated. Using data on the interaction potentials obtained in this study, the spin exchange cross sections are determined for the first time for the He(23 S 1)-Li(22 S 1/2) system in the interval of collision energies from 5 × 10−3 to 16 eV.

Technical Physics Letters•Dec 1, 2007•0 citations

Spin polarization transfer in ground and metastable helium atom collisions

D. Vrinceanu, H. R. Sadeghpour

Cross sections and rate constants for total elastic, diffusion and transfer of metastability for collisions between He(11S)–He(23S) and He(11S)–He(23P) atoms over a wide range of energies and temperatures are presented. The rate constant for spin metastability excitation in He(11S)–He(23P) collision is several orders of magnitude larger than that for He(11S)–He(23S) collision at cold temperatures, due to attractive 3Πg potential interaction.

New Journal of Physics•Jun 28, 2010•7 citations

He(11S)–He(23S) collision and radiative transition at low temperatures

D. Vrinceanu, H. R. Sadeghpour

There has been considerable recent interest in low-temperature interrogation of quantum helium nanodroplets. We consider the interaction of helium ground and metastable states, employing the best known molecular dimer potentials. Radiative transitions between different metastable rovibrational levels are compared with the discharge emission transition lines and good agreement is found. Collisional interactions between helium ground and metastable atoms are studied and elastic scattering, metastability excitation transfer and diffusion cross sections and rate coefficients are calculated at ultralow energies. The integral elastic cross section at ultralow energies is about $5000 {\mathrm{\AA{}}}^{2}.$ Effect of shape resonances that form in the potential barriers, on the cross sections is investigated. We find that some shape resonances live for longer than 100 s. Long-range potential wells could support ``shelf'' levels. We discuss their collisional and spectroscopic properties.

Physical Review A•Jun 13, 2002•10 citations

Magneto-Optical Trapping of Metastable Helium: Collisions in the Presence of Resonant Light

F Bardou, Olivier Émile, Jean-Michel Courty +2 more

About 10 4 triplet metastable helium atoms have been trapped in a magneto-optical trap, based on the 2 3 S 1 –2 3 P 2 transition at 1.083 μm (volume 0.1 mm 3 , temperature 1 mK). The losses of the trap are analysed by monitoring the ion current due to Penning collisions either with background gases, or between trapped atoms. The rate coefficient for these collisions between trapped metastable helium atoms has been found to be unusually large, and the crucial role of the quasi-resonant laser light has been experimentally demonstrated. The rate coefficient of the dominant process (He*(2 3 S 1 ) + He*(2 3 P 2 ) Penning collisions) has been measured by two different methods, and found to be K sp ≃ 10 -7 cm 3 s -1 within an estimated factor of 4. The corresponding cross-section is 6 · 10 6 Å 2 .

Europhysics Letters (EPL)•Dec 15, 1992•75 citations

Nonradiative formation of the positron-helium triplet bound state

Joseph Di Rienzi, Richard J. Drachman

We have previously calculated the cross section for radiative formation of the interesting bound state consisting of a positron bound to helium, where the atomic electrons are in the triplet spin state. That process uses the metastable triplet helium system as target, and, as expected, it has a very small cross section. In this paper we examine a more probable process in which the state of interest is produced in an exchange rearrangement collision between a positronium atom and the singlet helium ground state: $\mathrm{Ps}+\mathrm{He}(^{1}S^{\mathrm{e}})\ensuremath{\rightarrow}\mathrm{Ps}{\mathrm{He}}^{+}(^{3}S^{\mathrm{e}})+{e}^{\ensuremath{-}}$. The present calculation is done in the plane-wave Born approximation, using simple initial and final wave functions and compares post and prior forms.

Physical Review A•Feb 20, 2007•4 citations

Quenching of metastable He+ 2s ions by molecules

Govind P. Gupta, K. C. Mathur

A time-dependent perturbation theory is used to obtain the cross sections and rates for the quenching of metastable helium ions in collision with molecules (${\mathrm{H}}_{2}$, ${\mathrm{N}}_{2}$, ${\mathrm{O}}_{2}$, and C${\mathrm{O}}_{2}$). The results are compared with the recent experimental data of Prior and Wang.

Physical Review A•May 1, 1981•3 citations
Radiative association of metastable helium He(2 3 P) with lithium ions is theoretically investigated on the triplet-sigma manifold. Cross-sections and the corresponding rate coefficients for spontaneous and stimulated processes are calculated. Results are compared to other radiative and non-radiative processes in collisions of metastable helium with lithium ions.
There has been considerable recent interest in low-temperature interrogation of quantum helium nanodroplets. We consider the interaction of helium ground and metastable states, employing the best known molecular dimer potentials. Radiative transitions between different metastable rovibrational levels are compared with the discharge emission transition lines and good agreement is found. Collisional interactions between helium ground and metastable atoms are studied and elastic scattering, metastability excitation transfer and diffusion cross sections and rate coefficients are calculated at ultralow energies. The integral elastic cross section at ultralow energies is about 5000A˚2.5000 {\mathrm{\AA{}}}^{2}.5000A˚2. Effect of shape resonances that form in the potential barriers, on the cross sections is investigated. We find that some shape resonances live for longer than 100 s. Long-range potential wells could support ``shelf'' levels. We discuss their collisional and spectroscopic properties.
About 10 4 triplet metastable helium atoms have been trapped in a magneto-optical trap, based on the 2 3 S 1 –2 3 P 2 transition at 1.083 μm (volume 0.1 mm 3 , temperature 1 mK). The losses of the trap are analysed by monitoring the ion current due to Penning collisions either with background gases, or between trapped atoms. The rate coefficient for these collisions between trapped metastable helium atoms has been found to be unusually large, and the crucial role of the quasi-resonant laser light has been experimentally demonstrated. The rate coefficient of the dominant process (He*(2 3 S 1 ) + He*(2 3 P 2 ) Penning collisions) has been measured by two different methods, and found to be K sp ≃ 10 -7 cm 3 s -1 within an estimated factor of 4. The corresponding cross-section is 6 · 10 6 Å 2 .
We have previously calculated the cross section for radiative formation of the interesting bound state consisting of a positron bound to helium, where the atomic electrons are in the triplet spin state. That process uses the metastable triplet helium system as target, and, as expected, it has a very small cross section. In this paper we examine a more probable process in which the state of interest is produced in an exchange rearrangement collision between a positronium atom and the singlet helium ground state: $\mathrm{Ps}+\mathrm{He}(^{1}S^{\mathrm{e}})\ensuremath{\rightarrow}\mathrm{Ps}{\mathrm{He}}^{+}(^{3}S^{\mathrm{e}})+{e}^{\ensuremath{-}}$. The present calculation is done in the plane-wave Born approximation, using simple initial and final wave functions and compares post and prior forms.
A time-dependent perturbation theory is used to obtain the cross sections and rates for the quenching of metastable helium ions in collision with molecules (H2{\mathrm{H}}_{2}H2​, N2{\mathrm{N}}_{2}N2​, O2{\mathrm{O}}_{2}O2​, and CO2{\mathrm{O}}_{2}O2​). The results are compared with the recent experimental data of Prior and Wang.