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Full-Text Articles in Physics
Electron Energy Distributions From Multiple Ionization In 20–120-Kev H+ + Ar Collisions, Yang-Soo Chung, M. Eugene Rudd
Electron Energy Distributions From Multiple Ionization In 20–120-Kev H+ + Ar Collisions, Yang-Soo Chung, M. Eugene Rudd
M. Eugene Rudd Publications
Energy-analyzed secondary electrons from H+ + Ar collisions at eight proton energies from 20 to 120 keV were detected in coincidence with recoil ions of charge states 1–3. The charge states were distinguished by time-of-flight measurements and the electron energies were analyzed by a newly designed electrostatic analyzer of the low-pass high-pass filter type which has a large (~1.45π steradian) solid angle acceptance. For each of nine electron energies from 10 to 160 eV, the ionizing events associated with each residual ion charge state were counted. The electron energy dependence of the charge-state ratios and the average charge determined …
Doubly Differential Cross Sections Of Low-Energy Electrons Emitted In The Ionization Of Molecular Hydrogen By Bare Carbon Ions, Lokesh C. Tribedi, P. Richard, D. Ling, Y. D. Wang, C. D. Lin, R. Moshammer, G. W. Kerby Iii, M. W. Gealy, M. Eugene Rudd
Doubly Differential Cross Sections Of Low-Energy Electrons Emitted In The Ionization Of Molecular Hydrogen By Bare Carbon Ions, Lokesh C. Tribedi, P. Richard, D. Ling, Y. D. Wang, C. D. Lin, R. Moshammer, G. W. Kerby Iii, M. W. Gealy, M. Eugene Rudd
M. Eugene Rudd Publications
We have measured the double differential cross sections (DDCS) (d2σ/dεedΩe) of low-energy electron emission in the ionization of H2 bombarded by bare carbon ions of energy 30 MeV. The energy and angular distributions of the electron DDCS have been obtained for 12 different emission angles and for electron energies varying between 0.1 and 300 eV. We have also deduced the single differential and total ionization cross section from the measured DDCS. The data have been compared with the predictions of first Born approximations and the CDW-EIS (continuum distorted wave–eikonal …
The Observatory That Never Was, M. Eugene Rudd
The Observatory That Never Was, M. Eugene Rudd
M. Eugene Rudd Publications
Astronomy has been taught at the University of Nebraska since it first opened its doors in 1871, but for almost half of this time the university had no telescope larger than a Cinch Brashear refractor. Goodwin DeLoss Swezey, the astronomy professor at the turn of the century, had a small observatory built on campus to house this and other astronomical instruments.
Despite Swezey's ambitions for a larger telescope, the university's resources were limited. So he proposed to build a 12-inch refractor himself with the help of Charles S. Minnich, a nearby country doctor and amateur astronomer. Not only could Minnich …
New Model For Electron-Impact Ionization Cross Sections Of Molecules, W. Hwang, Y.-K. Kim, M. Eugene Rudd
New Model For Electron-Impact Ionization Cross Sections Of Molecules, W. Hwang, Y.-K. Kim, M. Eugene Rudd
M. Eugene Rudd Publications
A theoretical model for electron-impact ionization cross sections, which has been developed primarily for atoms and atomic ions, is applied to neutral molecules. The new model combines the binary-encounter theory and the Bethe theory for electron-impact ionization, and uses minimal theoretical data for the ground state of the target molecule, which are readily available from public-domain molecular structure codes such as GAMESS. The theory is called the binary encounter Bethe (BEB) model, and does not, in principle, involve any adjustable parameters. Applications to 19 molecules, including H2, NO, CH2, C6H6, and SF …
Energy And Angular Distributions Of Electrons From Ion Impact On Atomic And Molecular Hydrogen. Iv. 28–114-Kev He+ + H Collisions, Y.-Y. Hsu, M. W. Gealy, G. W. Kerby Iii, M. Eugene Rudd, D. R. Schultz, C. O. Reinhold
Energy And Angular Distributions Of Electrons From Ion Impact On Atomic And Molecular Hydrogen. Iv. 28–114-Kev He+ + H Collisions, Y.-Y. Hsu, M. W. Gealy, G. W. Kerby Iii, M. Eugene Rudd, D. R. Schultz, C. O. Reinhold
M. Eugene Rudd Publications
Absolute ionization cross sections for 28–114-keV helium ion impact on atomic hydrogen, differential in energy and angle of the ejected electrons, have been obtained from crossed-beam measurements and previously measured cross sections for molecular hydrogen targets. A radio frequency discharge source produced a mixed atomic and molecular target with a typical dissociation fraction of 74%. Energy spectra were measured from 1.5 to 130 eV by an electrostatic analyzer with a resolution of 5%. The angular range was 15° –160°. Results are compared with calculations based on the first Born, continuum-distorted-wave–eikonal-initial-state, and classical trajectory Monte Carlo methods. Total electron yields are …
Energy And Angular Distributions Of Electrons From Ion Impact On Atomic And Molecular Hydrogen. Iii. 28–114-Kev He+ + H2, Y.-Y. Hsu, M. W. Gealy, G. W. Kerby Iii, M. Eugene Rudd
Energy And Angular Distributions Of Electrons From Ion Impact On Atomic And Molecular Hydrogen. Iii. 28–114-Kev He+ + H2, Y.-Y. Hsu, M. W. Gealy, G. W. Kerby Iii, M. Eugene Rudd
M. Eugene Rudd Publications
Absolute cross sections, differential in energy and angle of ejection of the secondary electrons, were determined for electron emission from He+ +H2 collisions at 28–114 keV by measuring electron energy spectra from 1.5 to 300 eV at several angles from 15° to 160°. A rotatable electrostatic analyzer was used with an energy resolution of 5% and an angular acceptance of 4.6° full width at half maximum. The double-differential cross sections were integrated over angle, energy, or both to obtain single-differential and total ionization cross sections. The latter are in excellent agreement with previous experimental results. Agreement of the …