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University of Nebraska - Lincoln

1995

Paul Burrow Publications

Articles 1 - 3 of 3

Full-Text Articles in Physics

Electron-Impact Ionization Of Na, A.R. Johnston, Paul Burrow Mar 1995

Electron-Impact Ionization Of Na, A.R. Johnston, Paul Burrow

Paul Burrow Publications

Recent convergent close-coupling calculations of the ionization cross section of Na by Bray [Phys. Rev. Lett. 73, 1088 (1994)] are in poor agreement with the experimental determinations, most of which were carried out in the 1960s. We report here a measurement of the ratio of the peak ionization cross section to the cross section for excitation of the 32P state near threshold. By normalizing the latter to the theoretical cross section computed by Moores and Norcross [J. Phys. B 5, 1482 (1972)] and more recently by Trail et al. [Phys. Rev. A 49, 3620 (1994)], we find an ...


Dissociative Attachment In Hot Ch3Cl: Experiment And Theory, D. M. Pearl, Paul Burrow, Ilya I. Fabrikant, Gordon A. Gallup Feb 1995

Dissociative Attachment In Hot Ch3Cl: Experiment And Theory, D. M. Pearl, Paul Burrow, Ilya I. Fabrikant, Gordon A. Gallup

Paul Burrow Publications

The dissociative attachment (DA) cross section of hot CH3Cl has been measured in a crossed electron–molecule beam apparatus at temperatures up to 750 K and electron energies from 0–0.5 eV. The results are compared to cross sections computed using a mixed ab initio-semiempirical approach, treating CH3Cl as a quasidiatomic molecule. The theoretical treatment requires an anion potential curve in the stable region as a portion of the input data. Computations with three different basis sets show the results to be sensitive to the size of basis set from which the potential is ...


Temporary Negative-Ion States Of Na, K, Rb, And Cs, A.R. Johnston, Paul Burrow Jan 1995

Temporary Negative-Ion States Of Na, K, Rb, And Cs, A.R. Johnston, Paul Burrow

Paul Burrow Publications

Electron-transmission spectroscopy is used to observe structure in the electron-scattering cross section associated with the formation of temporary negative ions and channel-opening effects. A strong ‘‘family’’ resemblance is apparent among the resonances of the alkali metals. From published calculations and angular scattering studies, the lower-lying features are known with some confidence. Based on these, plausible assignments for some of the higher-lying resonances are put forth. We propose that the absence of resonances near the Cs 5 2D and possibly the Na 4 2P and 5 2P thresholds is associated with the negative polarizabilities of these excited states.