Energy relaxation in collisions of hydrogen and deuterium with oxygen atoms

Zhang, Peng; Kharchenko, V.; Jamieson, M. J.; Dalgarno, A.

doi:10.1029/2009ja014055

Cited by 21 publications

(26 citation statements)

References 37 publications

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“…Momentum transfer (or momentum transport) cross section (MTCS) is an effective quantity suitable for modeling the average momentum transferred from a projectile to the target particle in a binary collision. MTCSs are used in studies of energy exchange, diffusion, and transport in non-thermal en- vironments in astrophysics, atmospheric science, and aeronomy (Kharchenko et al 1997;Zhang et al 2009). For O( 3 P) + CO 2 ( j = 0) → O( 3 P) + CO 2 ( j = 0) elastic scattering, the momentum transfer cross section is given by…”

Section: Momentum Transfer Cross Sectionmentioning

confidence: 99%

O(3P) + CO2 scattering cross-sections at superthermal collision energies for planetary aeronomy

Gacesa

Lillis

Zahnle

2019

Monthly Notices of the Royal Astronomical Society

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We report new elastic and inelastic cross sections for O( 3 P)+CO 2 scattering at collision energies from 0.03 to 5 eV, of major importance to O escape from Mars, Venus, and CO 2 -rich atmospheres. The cross sections were calculated from first principles using three newly constructed ab-initio potential energy surfaces correlating to the lowest energy asymptote of the complex. The surfaces were restricted to a planar geometry with the CO 2 molecule assumed to be in linear configuration fixed at equilibrium. Quantum-mechanical coupled-channel formalism with a large basis set was used to compute state-to-state integral and differential cross sections for elastic and inelastic O( 3 P)+CO 2 scattering between all pairs of rotational states of CO 2 molecule. The elastic cross sections are 35% lower at 0.5 eV and more than 50% lower at 4+ eV than values commonly used in studies of processes in upper and middle planetary atmospheres of Mars, Earth, Venus, and CO 2 -rich planets. Momentum transfer cross sections, of interest for energy transport, were found to be proportionally lower than predicted by mass-scaling.

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Section: Momentum Transfer Cross Sectionmentioning

confidence: 99%

O(3P) + CO2 scattering cross-sections at superthermal collision energies for planetary aeronomy

Gacesa

Lillis

Zahnle

2019

Monthly Notices of the Royal Astronomical Society

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“…Due to the lack of data for collisions between hot oxygen and CO 2 or CO, the same total and differential cross sections and energy loss rates as for O−N 2 collisions are employed. Collisions of hot oxygen with H and He are treated by means of the elastic collision cross section for O−H collisions given in Zhang et al (2009). For the collisions of hot oxygen atoms with other background atoms, the data for O−O collisions are used.…”

Section: Collisions Between O( 3 P 1 D 1 S) and Other Atoms And Molmentioning

confidence: 99%

Hot oxygen and carbon escape from the martian atmosphere

Gröller

Lichtenegger

Lämmer

et al. 2014

Planetary and Space Science

107

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The escape of hot O and C atoms from the present martian atmosphere during low and high solar activity conditions has been studied with a Monte-Carlo model. The model includes the initial energy distribution of hot atoms, elastic, inelastic, and quenching collisions between the suprathermal atoms and the ambient cooler neutral atmosphere, and applies energy dependent total and differential cross sections for the determination of the collision probability and the scattering angles. The results yield a total loss rate of hot oxygen of 2.3 − 2.9 × 10 25 s −1 during low and high solar activity conditions and is mainly due to dissociative recombination of O + 2 and CO + 2 . The total loss rates of carbon are found to be 0.8 and 3.2×10 24 s −1 for low and high solar activity, respectively, with photodissociation of CO being the main source. Depending on solar activity, the obtained carbon loss rates are up to ∼ 40 times higher than the CO + 2 ion loss rate inferred from Mars Express ASPERA-3 observations. Finally, collisional effects above the exobase reduce the escape rates by about 20-30% with respect to a collionless exophere.

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“…For O( 3 P), they are 3 Π, 3 Σ with weights 2/3 and 1/3. Computed total and diffusion cross sections [ Zhang et al , 2009] are shown in Figure 1 for both He isotopes. Interestingly, the cross sections for O( 3 P) and O( 1 D) show a very similar energy dependence with small differences appearing only in the high energy region, where scattering is dominated by the repulsive part of the interaction potential.…”

Section: Quantum Cross Sections and Energy Transfer In O+he Collisionsmentioning

confidence: 99%

Energy transfer in O collisions with He isotopes and Helium escape from Mars

Bovino

Zhang

Gianturco

et al. 2011

Geophys. Res. Lett.

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[1] Accurate data on energy-transfer collisions between hot oxygen atoms and the atmospheric helium gas on Mars, are reported. Anisotropic cross sections for elastic collisions of O( 3 P) and O( 1 D) atoms with helium gas have been calculated quantum mechanically and found to be surprisingly similar. Cross sections, computed for collisions with both helium isotopes, 3 He and 4 He, have been used to construct the kernel of the Boltzmann equation describing the energy relaxation of hot oxygen atoms. Computed rates of energy transfer in O+He collisions have been used to evaluate the flux of He atoms escaping from the Mars atmosphere. Atmospheric layers mostly responsible for production of the He escape flux are identified. Our results demonstrate that strong angular anisotropy of scattering cross sections increases the collisional ejection of light atoms and is critical in the evaluation of He escape from Mars, Venus and Earth. Citation: Bovino, S.,

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Energy relaxation in collisions of hydrogen and deuterium with oxygen atoms

Abstract: [1] Collision energy transfer processes between hydrogen, deuterium, and oxygen atoms in the upper atmospheres of the terrestrial planets are studied. A new set of interaction potentials has been constructed using an accurate ab initio method.

Cited by 21 publications

References 37 publications

O(3P) + CO2 scattering cross-sections at superthermal collision energies for planetary aeronomy

O(3P) + CO2 scattering cross-sections at superthermal collision energies for planetary aeronomy

Hot oxygen and carbon escape from the martian atmosphere

Energy transfer in O collisions with He isotopes and Helium escape from Mars

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