SPECTRA, EMISSION YIELDS, CROSS SECTIONS, AND KINETIC ENERGY DISTRIBUTIONS OF HYDROGEN ATOMS FROM H<sub>2</sub>
	  –
	   EXCITATION BY ELECTRON IMPACT

Liu, Xianming; Shemansky, D. E.; Yoshii, J.; Johnson, P. V.; Malone, C. P.; Ajello, J. M.

doi:10.3847/0004-637x/818/2/120

Cited by 6 publications

(20 citation statements)

References 117 publications

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“…As the integration includes a q ( ) sin weighting, which heavily weights out the contribution to the ICS from the unmeasured angular regions, the difference between the assumed extrapolation and the flat-extrapolation is generally around 2%. Based on the work of Liu et al [32,33], the cross section of a…”

Section: Data Acquisition and Analysismentioning

confidence: 99%

“…) and an appropriate rotational factor (or a sum of rotational factors). The rotational factor for different electronic excitations of H 2 have been given in Liu et al [32][33][34][35][36]. The electronic form factor, which accounts for magnitude and excitation energy dependence of the cross section, can be considered as a common factor for a given electronic excitation at a given energy.…”

Section: Data Acquisition and Analysismentioning

confidence: 99%

“…For all other states, the BO potentials and adiabatic corrections of Wolniewicz [38], Staszewska and Wolniewicz [39][40][41], along with appropriate relativistic and radiative corrections, were used. The construction of the singlet-ungerade and triplet potentials has been described by Liu et al [33,36,42]. In the absence of the non-adiabatic correction, the obtained vibrational wave [48]) were used to calculate ro-vibronic transition frequencies.…”

Section: Data Acquisition and Analysismentioning

confidence: 99%

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Differential cross sections for excitation of H₂by low-energy electron impact

Hargreaves

Bhari

Adjari

et al. 2017

J. Phys. B: At. Mol. Opt. Phys.

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Experimental and theoretical differential cross sections (DCS) for the electron-impact excitation of molecular hydrogen to the S + B u, and thestates are presented at incident energies near to threshold. The experimental DCSs were taken at incident energies of 14, 15, 16 and 17.5 eV and for scattering angles from 10°to 130°. The theoretical DCSs are from the convergent close-coupling method which has recently successfully modeled differential electron scattering from H 2 when compared with available experiment at energies of 17.5 eV and above.

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Section: Data Acquisition and Analysismentioning

confidence: 99%

Section: Data Acquisition and Analysismentioning

confidence: 99%

Section: Data Acquisition and Analysismentioning

confidence: 99%

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Differential cross sections for excitation of H₂by low-energy electron impact

Hargreaves

Bhari

Adjari

et al. 2017

J. Phys. B: At. Mol. Opt. Phys.

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“…Accurate calculation of some high (v, N) levels of the a g 3 S + and c u 3 P states of the heavy isotopologues such as DT and T 2 requires the potential up to 600 to 1000 a 0 . The three term extrapolation based on the last 3 points of the potential around 44 a 0 used in our previous work (Liu et al 2012(Liu et al , 2016(Liu et al , 2017a) is insufficient. The H 2 b u 3 S + long range potential of Ovsiannikov and Mitroy (2006) and the a g 3 S + , c u 3 P , B¢ u 1 S + and D u 1 P long range potentials of Vrinceanu and Dalgarno (2008) are used to extend V(R) to the required ranges of R (see also Liu et al 2017b).…”

Section: Potential Energy Curvesmentioning

confidence: 99%

Isotope dependence of thec³Π_u−b³Σ${}_{u}^{+}$ andD¹Π${}_{u}^{+}$−B′¹Σ${}_{u}^{+}$ predissociation rates of molecular hydrogen

et al. 2019

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The state-specific predissociation rates of the c u 3 P (v,N,J) state by b u 3 S + and the D u 1 P + (v,J) state by the B¢ u 1 S + continuum of various isotopologues of molecular hydrogen have been calculated from accurate ab initio potential energy curves and electronic coupling matrix elements. Lifetimes and predissociation rates of the c u 3 P (v,N,J) and D u 1 P + (v,J) levels and accurate energies of the c u 3 P -(v,N) and D u 1 P -(v,J) levels of the isotopologues have been obtained. Significant isotope dependence of state specific predissociation rate has been found even after adjustment for Franck-Condon factors and reduced mass. The use of average electronic matrix elements of H 2 for other isotopologues underestimates the c u 3 P + −b u 3 S + predissociation rates of the HD, HT, D 2 , DT and T 2 molecules by ∼12%, ∼16%, ∼30%, ∼40%, ∼52%, respectively, and the D u 1 P + −B¢ u 1 S + rates of the HD, HT, D 2 , DT and T 2 molecules by ∼10%, ∼15%, ∼26%, ∼35% and ∼45%, respectively. When compared at similar rotation, vibration and kinetic energies, the underestimation is nearly independent of the kinetic energy. The absolute value of the average electronic coupling matrix element increases with the reduced mass while that of the vibrational overlap integral decreases with the reduced mass. This accidental substantial cancellation in the D u 1 P + −B¢ u 1 S + system is responsible for the experimental observation that the relative D u 1 P + predissociation rate of two isotopologues approximately equals the squared inverse reduced mass ratio. The origin and implications of the isotope dependence of the averaged electronic coupling matrix elements are discussed.

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“…states for H 2 have been given in Liu et al (2016). In going from H 2 to HD and D 2 , the only change in the potential of equation ( 15) is the V R adi ( ), which is inversely proportional to the reduced mass of nuclei.…”

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confidence: 99%

Energies, transition probabilities, predissociation rates, and lifetimes of the ${{\rm{H}}}_{2}$, HD, and ${{\rm{D}}}_{2}$ $c{}^{3}{{\rm{\Pi }}}_{u}^{-}$ state

Liu

Shemansky

Yoshii

et al. 2017

J. Phys. B: At. Mol. Opt. Phys.

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Transition probabilities of H 2 , HD, and D 2 Pc u 3 − S + a g 3 electric dipole, Pc u 3 − S + b u 3 discretecontinuum magnetic dipole, and electric quadrupole transitions have been calculated using accurate energies and ro-vibrational wave functions obtained from precise ab initio potential energy curves. The predissociation rates of the Pc u 3 (v N , ) levels by direct and indirect spinspin and spin-orbit coupling between Pc u 3 − S + b u 3 fine structure levels, have been also determined. The present investigation achieved good agreement with measured lifetimes of the Pc u 3 fine structure levels without adjustment. A comparison of the calculated and observed lifetimes of metastable H 2 , HD, and D 2 suggests that the Pc u 3 − S + b u 3 magnetic dipole and electric quadrupole transition moments underestimate the spontaneous emission rate of the metastable levels by ∼370 s −1 . The measured and calculated lifetimes of H 2 , HD, and D 2 fine structure levels are in very good agreement after the adjustment of 370 s −1 to the spontaneous decay rate of the Pc u 3 − S + b u 3 transition. The calculated energies, transition probabilities, and predissociation rates obtained in the present work, along with the P c u 3 state excitation function, are sufficient to determine the P c u 3 state emission cross section, the kinetic energy distribution of H(1s) atoms, and the energy deposition rate of the S + X g 1 − P c u 3 excitation. In a previous investigation by Berg and Ottinger (1994 J. Chem. Phys. 100 8746), the authors were forced to insert a large scale factor into the predissociation rate in order to reconcile with measured lifetimes. Errors introduced in the approximations made in the previous investigations are discussed in the text. The H 2 P c u 3 state has the second largest triplet state excitation cross section. Predissociation and spontaneous emission of the P c u 3 state plays an important role in the energy deposition of H 2 -dominated atmospheres.

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SPECTRA, EMISSION YIELDS, CROSS SECTIONS, AND KINETIC ENERGY DISTRIBUTIONS OF HYDROGEN ATOMS FROM H₂ – EXCITATION BY ELECTRON IMPACT

Abstract: Electron-impact excitation of H2 triplet states plays an important role in the heating of outer planet upper thermospheres. The Show more

Cited by 6 publications

References 117 publications

Differential cross sections for excitation of H₂by low-energy electron impact

Differential cross sections for excitation of H₂by low-energy electron impact

Isotope dependence of thec³Π_u−b³Σ${}_{u}^{+}$ andD¹Π${}_{u}^{+}$−B′¹Σ${}_{u}^{+}$ predissociation rates of molecular hydrogen

Energies, transition probabilities, predissociation rates, and lifetimes of the ${{\rm{H}}}_{2}$, HD, and ${{\rm{D}}}_{2}$ $c{}^{3}{{\rm{\Pi }}}_{u}^{-}$ state

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SPECTRA, EMISSION YIELDS, CROSS SECTIONS, AND KINETIC ENERGY DISTRIBUTIONS OF HYDROGEN ATOMS FROM H2 – EXCITATION BY ELECTRON IMPACT

Abstract: Electron-impact excitation of H2 triplet states plays an important role in the heating of outer planet upper thermospheres. The Show more

Cited by 6 publications

References 117 publications

Differential cross sections for excitation of H2by low-energy electron impact

Differential cross sections for excitation of H2by low-energy electron impact

Isotope dependence of thec3Πu−b3Σ${}_{u}^{+}$ andD1Π${}_{u}^{+}$−B′1Σ${}_{u}^{+}$ predissociation rates of molecular hydrogen

Energies, transition probabilities, predissociation rates, and lifetimes of the ${{\rm{H}}}_{2}$, HD, and ${{\rm{D}}}_{2}$ $c{}^{3}{{\rm{\Pi }}}_{u}^{-}$ state

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SPECTRA, EMISSION YIELDS, CROSS SECTIONS, AND KINETIC ENERGY DISTRIBUTIONS OF HYDROGEN ATOMS FROM H₂ – EXCITATION BY ELECTRON IMPACT

Differential cross sections for excitation of H₂by low-energy electron impact

Differential cross sections for excitation of H₂by low-energy electron impact

Isotope dependence of thec³Π_u−b³Σ${}_{u}^{+}$ andD¹Π${}_{u}^{+}$−B′¹Σ${}_{u}^{+}$ predissociation rates of molecular hydrogen