Kinetic-energy release of fragments from electron-impact dissociation of the molecular hydrogen ion and its isotopologues

Abstract

We calculate the kinetic energy release distributions of fragments produced for electron-impact dissociation of the vibrationally excited molecular hydrogen ion H + 2 and its isotopologues D + 2 and T + 2 . Here we apply the adiabatic-nuclei convergent close-coupling method and compare results with several different methods, including the delta approximation. Results are presented for a number of dissociative excitation transitions and dissociative ionization as a function of the initial vibrational state of the molecule. We confirm that the "square root" approximation is a good approximation for the adiabatic-nuclei kinetic energy release cross sections of H + 2 . Agreement with experiment, where available, is good.

Vibrationally resolved electron-impact excitation cross sections for singlet states of molecular hydrogen

“…The calculations were convergent with respect to the number of coupled channels over the entire 10-300eV energy range, and yielded electronic excitation and ionization cross sections in good agreement with experiment [20,21]. The CCC method has been applied in the AN approximation to investigate electron collisions with + H 2 [22,23], positron collisions with H 2 [24], and low-energy electron-impact dissociation of H 2 [25], yielding good agreement with experiment in each case. The AN CCC method has also been utilized to calculate electron-impact dissociation of the H 2 ground state into neutral fragments over wide range of incident electron energies (6-300 eV) [26].…”

Convergent close-coupling approach to light and heavy projectile scattering on atomic and molecular hydrogen

“…The molecular CCC method is formulated in the FN approximation. Its application to electron [40,41,[193][194][195], positron [42,43], and heavy particle [196] collisions with molecular hydrogen and its ion has been detailed previously [197]. Here we give only a short overview.…”

Photoionization from the Ground and Excited Vibrational States of H2+ and Its Deuterated Isotopologues

“…For v 4, the cross sections near their respective thresholds increase significantly in magnitude as the vibrational level v increases. The increase in the magnitude of the cross section as v increases is also observed in electron scattering and photodissociation of + H 2 (Zammit et al 2014;Scarlett et al 2017;Zammit et al 2017), and electron scattering from H 2 (Scarlett et al 2021a). However, for v 3 the near-threshold cross section decreases as v increases.…”