H[sup +]-H[sup [minus]] coincidences from the three-body dissociation of excited H[sub 3][sup +]

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.47.1059· OSTI ID:6743213

Yenen, O; Calabrese, D; Wiese, L M; Jaecks, D H ^[1]; Gallup, G A ^[2]

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1. Behlen Laboratory of Physics, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States)
2. Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304 (United States)

The laboratory energy distribution of protons in coincidence with an H[sup [minus]] ion, resulting from the dissociation of excited H[sub 3][sup +], has been measured for H[sup +]-H[sup [minus]] pairs emitted along the beam for 4.0-keV H[sub 3][sup +]-He collisions. An approximate energy distribution of H[sup +]-H[sup [minus]] pairs for the collinear configuration of the dissociation products is obtained by transforming the measured laboratory spectrum to the H[sub 3][sup +] center-of-mass (c.m.) frame. Coincidence data suggest that the reaction producing H[sup +]-H[sup [minus]] pairs where the H[sup +] ion has near-zero energies ([lt]0.5 eV) in the c.m. frame is a low-probability process. We have also computed the adiabatic Born-Oppenheimer energies of H[sub 3][sup +] ions using a full configuration-interaction calculation with a basis set of atomic orbitals consisting of 1[ital s], 1[ital s][prime], 1[ital p][prime], 2[ital s], and 2[ital p] centered on the protons forming an isosceles ([ital C][sub 2[ital v]] symmetry) or an equilateral ([ital D][sub 3[ital h]] symmetry) triangle. The states leading to asymptotic H[sup +]+H[sup +]+H[sup [minus]] limits have been identified by calculating [l angle]1/[ital r][sub 12][r angle][sup [minus]1], the inverse of the expectation value of the electron-electron repulsion term. The states identified by this procedure have adiabatic Born-Oppenheimer energies of 40--45 eV above the H[sub 3][sup +] ground state at the H[sub 3][sup +] equilibrium separation. The limits on the total available internal energy to be shared by the three dissociation products that one obtains from the experimentally determined H[sup +]-H[sup [minus]] coincidence spectrum are consistent with the identified H[sub 3][sup +] excited states.

• OSTI ID: 6743213
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 47:2; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ANIONS
BARYONS
BORN-OPPENHEIMER APPROXIMATION
CATIONS
CHARGED PARTICLES
COINCIDENCE METHODS
COUNTING TECHNIQUES
DISSOCIATION
ELECTRON-ELECTRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY LEVELS
EXCITED STATES
FERMIONS
HADRONS
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
HYDROGEN IONS 1 PLUS
INTERACTIONS
IONS
LEPTON-LEPTON INTERACTIONS
MANY-BODY PROBLEM
NUCLEONS
PARTICLE INTERACTIONS
PROTONS
THREE-BODY PROBLEM