Ionization of H by protons colliding at near threshold in adiabatic treatment

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Physical Review, A; (USA)

DOI:https://doi.org/10.1103/PhysRevA.42.3865· OSTI ID:6060605

Ovchinnikov, S Y ^[1]

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1. Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (USA)

Ionization in H(1{ital s})+H{sup +} collisions is studied near the threshold and at relative collision energies in the range 5--25 keV. Based on the analytic continuation of the adiabatic potential-energy curves in the complex plane of the internuclear distance, the transition probabilities are calculated in the WKB approximation by evaluating the phase integral around the branch points connecting the potential curves. Two different ionization mechanisms are identified: one is the propagation on a ridge of the centrifugal core of the electronic potential when the nuclei approach each other, and the other is associated with the saddle point of the two-center Coulomb potential. The two mechanisms give about equal contributions to the total ionization cross section in the relative energy range 5.0--25.0 keV. Near threshold the second mechanism dominates. The analytical threshold energy-dependence behavior differs from the Wannier law.

• OSTI ID: 6060605
• Journal Information: Physical Review, A; (USA), Journal Name: Physical Review, A; (USA) Vol. 42:7; ISSN 1050-2947; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ADIABATIC APPROXIMATION
ATOM COLLISIONS
CATIONS
CHARGED PARTICLES
COLLISIONS
ELEMENTS
ENERGY RANGE
HYDROGEN
HYDROGEN IONS
HYDROGEN IONS 1 PLUS
ION COLLISIONS
ION-ATOM COLLISIONS
IONIZATION
IONS
KEV RANGE
KEV RANGE 01-10
KEV RANGE 10-100
NONMETALS
WKB APPROXIMATION