Experimental evidence for the existence of the 2[ital p][sigma] bound state of HeH[sup 2+] and its decay mechanism

Journal Article · Mon Aug 30 00:00:00 EDT 1993 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.71.1347· OSTI ID:6214292

Ben-Itzhak, I ^[1]; Gertner, I; Heber, O; Rosner, B ^[2]

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1. James R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States)
2. Department of Physics, Technion, Haifa 32000 (Israel)

Experimental evidence of the existence of a bound state of the HeH[sup 2+] molecular ion is presented. Bates and Carson predicted a bound 2[ital p][sigma] state in spite of the strong repulsion potential between the two nuclei. Decay is expected by an electronic transition to the 1[ital s][sigma] repulsive ground state with a mean lifetime of about 1 nsec and a kinetic energy release of [similar to]7 eV. A novel coincidence technique was developed for the measurement of metastable molecular ions which dissociate in flight before reaching the detector. The metastable HeH[sup 2+] ions were produced in collisions of 900 keV HeH[sup +] with Ar and analyzed within a few nanoseconds using a small powerful analyzing magnet. The coincidences between the H[sup +] and He[sup +] fragments detected at the deflection angle associated with the HeH[sup 2+] molecular ion indicate clearly that it was formed in a bound state during the collision and decayed after passing through the analyzer. The radial distribution of fragments hitting the detector was also measured and the kinetic energy-released in the dissociation was determined. This energy was found to be consistent with the one expected for the decay of HeH[sup 2+] by 2[ital p][sigma] to 1[ital s][sigma] transition.

• OSTI ID: 6214292
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 71:9; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

664400* -- Experimentally Derived Information on Atomic & Molecular Properties-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
BOUND STATE
CATIONS
CHARGED PARTICLES
DATA
DISSOCIATION
ENERGY LEVELS
EXPERIMENTAL DATA
GROUND STATES
HELIUM COMPOUNDS
HELIUM HYDRIDES
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
IONS
LIFETIME
MANY-BODY PROBLEM
NUMERICAL DATA
RARE GAS COMPOUNDS
THREE-BODY PROBLEM
TRAJECTORIES