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Full-Text Articles in Physics
Doubly Differential Single And Multiple Ionization Of Krypton By Electron Impact, O. G. De Lucio, Jared M. Gavin, Robert D. Dubois
Doubly Differential Single And Multiple Ionization Of Krypton By Electron Impact, O. G. De Lucio, Jared M. Gavin, Robert D. Dubois
Physics Faculty Research & Creative Works
Differential measurements for single and multiple ionization of Kr by 240 and 500 eV electron impact are presented. Using a pulsed extraction field, Kr+, Kr2+, and Kr3+ ions were measured in coincidence with scattered electrons for energy losses up to 120 eV and scattering angles between 16° and 90°. Scaling properties of the doubly differential cross sections (DDCS) are investigated as a function of energy loss, scattering angle, and momentum transfer. It is shown that scaling the DDCS as outlined by Kim and Inokuti and plotting them versus a parameter consisting of the momentum transfer divided by the square root …
Theoretical Treatment Of Electron-Impact Ionization Of Molecules, Junfang Gao, Jerry Peacher, Don H. Madison
Theoretical Treatment Of Electron-Impact Ionization Of Molecules, Junfang Gao, Jerry Peacher, Don H. Madison
Physics Faculty Research & Creative Works
There is currently no reliable theory for calculating the fully differential cross section (FDCS) for low energy electron-impact ionization of molecules. All of the existing experimental FDCS data represent averages over all molecular orientations and this can be an important theoretical complication for calculations that are computer intensive. We have found that using an averaged molecular orbital is an accurate approximation for ionization of ground states. In this paper, we will describe the approximation, discuss its expected range of validity and show some FDCS results using the approximation for ionization of H2 and N2
Experimental And Theoretical (E,2e) Ionization Cross Sections For A Hydrogen Target At 75.3 Ev Incident Energy In A Coplanar Asymmetric Geometry, Junfang Gao, Don H. Madison, Jerry Peacher, Andrew James Murray, Martyn J. Hussey
Experimental And Theoretical (E,2e) Ionization Cross Sections For A Hydrogen Target At 75.3 Ev Incident Energy In A Coplanar Asymmetric Geometry, Junfang Gao, Don H. Madison, Jerry Peacher, Andrew James Murray, Martyn J. Hussey
Physics Faculty Research & Creative Works
Very recently it was shown that the molecular three-body distorted wave (M3DW) approach gives good agreement with the shape of the experimental data for electron-impact ionization of H2 in a coplanar symmetric geometry, providing the incident electrons have an energy of 35 eV or greater. One of the weaknesses of these studies was that only the shape of the cross section could be compared to experiment, since there was no absolute or relative normalization of the data. Here we report a joint experimental/theoretical study of electron-impact ionization of H2 in a coplanar asymmetric geometry where the energy of …
Distorted Wave Born And Three-Body Distorted Wave Born Approximation Calculations Of The Fully Differential Cross Section For Electron-Impact Ionization Of Nitrogen Molecules, Junfang Gao, Don H. Madison, Jerry Peacher
Distorted Wave Born And Three-Body Distorted Wave Born Approximation Calculations Of The Fully Differential Cross Section For Electron-Impact Ionization Of Nitrogen Molecules, Junfang Gao, Don H. Madison, Jerry Peacher
Physics Faculty Research & Creative Works
Currently there are no reliable theoretical approaches for calculating fully differential cross sections (FDCSs) for low-energy electron-impact ionization of large molecules. We have recently proposed the orientation-averaged molecular orbital (OAMO) for calculating cross sections averaged over molecular orientations. In this paper, we use the OAMO to calculate distorted wave Born approximation (DWBA) and molecular three-body distorted wave (M3DW) Born approximation FDCS for electron-impact ionization of the nitrogen molecule. Both coplanar symmetric and asymmetric FDCSs are investigated in the energy range of 35.6-400 eV. by comparing with the experimental data, we found that the M3DW is reasonably accurate in this energy …
An Elementary Method For Calculating Orientation-Averaged Fully Differential Electron-Impact Ionization Cross Sections For Molecules, Junfang Gao, Jerry Peacher, Don H. Madison
An Elementary Method For Calculating Orientation-Averaged Fully Differential Electron-Impact Ionization Cross Sections For Molecules, Junfang Gao, Jerry Peacher, Don H. Madison
Physics Faculty Research & Creative Works
Currently there are no reliable theoretical approaches for calculating fully differential cross sections (FDCS) for low-energy electron-impact ionization of large molecules. We have recently introduced the distorted-wave impulse approximation as a first step in developing improved theoretical approaches. One significant obstacle to evaluating improved theoretical approaches which require significant computer resources lies in the fact that the existing experimental data require taking averages over all molecular orientations. To circumvent this problem, it has been proposed to approximate the orientation-average by using an orientation-averaged molecular orbital in the calculation of the FDCS. The theoretical justification and expected range of validity for …