Near-zero energy proton production mechanisms from the three-body dissociation of H sub 3 sup +

Journal Article · Sun Jul 01 04:00:00 EDT 1990 · Physical Review, A (General Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevA.42.324· OSTI ID:6506543

Yenen, O; Wiese, L M; Calabrese, D; Jaecks, D H ^[1]

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1. Behlen Laboratory of Physics, University of Nebraska, Lincoln, NE (USA)

The laboratory energy distribution of H{sup +} from the dissociation of H{sub 3}{sup +} in low-keV H{sub 3}{sup +}-He collisions is measured at a 0{degree} laboratory angle. An inelastic energy loss of {ital Q}=26{plus minus}2 eV has been determined for the excited states of H{sub 3}{sup +} that produce low-energy protons upon dissociation. An approximate projectile-frame energy distribution of H{sup +} is also presented. Our results suggest that the near-zero projectile-frame energy protons are produced by either an electronic singlet excitation of the ground state of H{sub 3}{sup +} to a distribution of 2{sup 1}{ital E}{prime}, 1{sup 1}{ital E}{prime}{prime}, and 2 {sup 1}A{sub 2}{sup {prime}{prime}}, or as an alternative mechanism, a triplet excitation of H{sub 3}{sup +} to 1{sup 3}{ital E}{prime} accompanied by a simultaneous triplet excitation of the He target. In either case, the near-zero energy protons are produced by a three-body dissociation of the excited (H{sub 3}{sup +}){sup *}. In the case of the triplet excitation, there are no long-range correlations for the motion of the neutral H atoms. For the singlet excitation, the neutral H atoms' motion is correlated and the angle between them is near 180{degree}. The effects of the long-range nature of the total potential between the fragments is discussed in terms of the hyperspherical coordinates.

• OSTI ID: 6506543
• Journal Information: Physical Review, A (General Physics); (USA), Journal Name: Physical Review, A (General Physics); (USA) Vol. 42:1; ISSN PLRAA; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
BARYONS
CATIONS
CHARGED PARTICLES
COLLISIONS
DISSOCIATION
ELEMENTARY PARTICLES
ELEMENTS
ENERGY SPECTRA
FERMIONS
FLUIDS
GASES
HADRONS
HELIUM
HYDROGEN IONS
HYDROGEN IONS 3 PLUS
ION COLLISIONS
ION-ATOM COLLISIONS
IONS
KINETICS
MANY-BODY PROBLEM
MOLECULAR IONS
NONMETALS
NUCLEONS
PROTONS
RARE GASES
SCATTERING
SMALL ANGLE SCATTERING
SPECTRA
THREE-BODY PROBLEM