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dc.contributor.advisor Dunning, F. B.
dc.creatorLiu, Yi
dc.date.accessioned 2009-06-03T19:54:45Z
dc.date.available 2009-06-03T19:54:45Z
dc.date.issued 2008
dc.identifier.citation Liu, Yi. "Study of dipole-bound negative ions: Formational dynamics and collisional properties." (2008) Diss., Rice University. https://hdl.handle.net/1911/22194.
dc.identifier.urihttps://hdl.handle.net/1911/22194
dc.description.abstract Electron transfer in collisions between atoms in high Rydberg states and polar targets can lead to the formation of dipole-bound negative ions in which the excess electron is weakly bound by the dipole potential of the neutral molecule. Their lifetimes and collisional destruction rates are studied using a Penning ion trap. Ion decay in the trap is characterized by a single exponential lifetime, ∼60 to 100 mus governed by BBR-induced photodetachment. The rate constants for destruction of these ions by rotational energy transfer in collisions with residual target gas present in the trap are large, ∼ 10-7cm3s-1. The dynamics of CH3CN- ion production through electron transfer are examined using velocity selected Rydberg atoms. The CH3CN- ion formation rate shows a strong velocity dependence and is relatively small, the associated rate constants being ∼ 0.5--1.0 x 10-8cm 3s-1. A curve-crossing model, which considers the effect of crossings between the diabatic potential curves for the covalent K(np)/CH3CN system and the ionic K+/CH 3CN- system is discussed and provides a clear explanation for the observations. Electron transfer in collisions between dipole-bound negative ions (CH 3CN- and C2H3CN-) and target gas, including attaching molecules like SF6 and polar molecules like CH3NO2, is examined using the Penning trap. A free-electron capture model is used to describe electron transfer to attaching molecules. A near-resonant charge transfer model is employed to describe collisions between dipole-bound anions and polar molecules. The rate constants predicted by these models are consistent with the experimental observations.
dc.format.extent 132 p.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectAtomic physics
dc.title Study of dipole-bound negative ions: Formational dynamics and collisional properties
dc.type Thesis
dc.type.material Text
thesis.degree.department Physics
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy


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