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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
A Dynamical (E,2e) Investigation Into The Ionization Of The Outermost Orbitals Of R-Carvone, D. B. Jones, E. Ali, C. G. Ning, F. Ferreira Da Silva, O. Ingolfsson, M. C. A. Lopes, H. S. Chakraborty, Don H. Madison, M. J. Brunger
A Dynamical (E,2e) Investigation Into The Ionization Of The Outermost Orbitals Of R-Carvone, D. B. Jones, E. Ali, C. G. Ning, F. Ferreira Da Silva, O. Ingolfsson, M. C. A. Lopes, H. S. Chakraborty, Don H. Madison, M. J. Brunger
Physics Faculty Research & Creative Works
We report an experimental and theoretical investigation into the dynamics of electron-impact ionization of R-carvone. Experimental triple differential cross sections are obtained in asymmetric coplanar kinematic conditions for the ionization of the unresolved combination of the three outermost molecular orbitals (41a-39a) of R-carvone. These cross sections are compared with theoretical cross sections calculated within a molecular 3-body distorted wave (M3DW) framework employing either a proper orientation average or orbital average to account for the random orientation of the molecule probed in the experiment. Here, we observe that the overall scattering behavior observed in the experiment is fairly well reproduced within …
Low-Energy (E₀ = 65 Ev) Electron-Impact Ionization Of Neon: Internormalized Triple-Differentical Cross Sections In 3d Kinematics, Xueguang Ren, Sadek M. Amami, Oleg I. Zatsarinny, Thomas Pfluger, Marvin Weyland, Woon Yong Baek, Hans Rabus, Klaus Bartschat, Don H. Madison, Alexander Dorn
Low-Energy (E₀ = 65 Ev) Electron-Impact Ionization Of Neon: Internormalized Triple-Differentical Cross Sections In 3d Kinematics, Xueguang Ren, Sadek M. Amami, Oleg I. Zatsarinny, Thomas Pfluger, Marvin Weyland, Woon Yong Baek, Hans Rabus, Klaus Bartschat, Don H. Madison, Alexander Dorn
Physics Faculty Research & Creative Works
We present a combined experimental and theoretical study on the low-energy (E0 = 65 eV) electron- impact ionization of neon. The experimental data are compared to predictions from a hybrid second-order distorted-wave Born plus R-matrix approach (DWB2-RM), the distorted-wave Born approximation with inclusion of post-collision interaction (DWBA-PCI), a three-body distorted-wave approach (3DW), and a B-spline R-matrix (BSR) with pseudostates approach. Excellent agreement is found between experiment and the 3DW and BSR theories. The importance of PCI effects is clearly visible in this low-energy electron-impact ionization process.
Experimental And Theoretical Cross Sections For Molecular-Frame Electron-Impact Excitation-Ionization Of D₂, Julian C A Lower, Esam S M Ali, Susan M. Bellm, Erich Weigold, Allison L. Harris, Chuangang Ning, Don H. Madison
Experimental And Theoretical Cross Sections For Molecular-Frame Electron-Impact Excitation-Ionization Of D₂, Julian C A Lower, Esam S M Ali, Susan M. Bellm, Erich Weigold, Allison L. Harris, Chuangang Ning, Don H. Madison
Physics Faculty Research & Creative Works
We present both experimental and theoretical results for the dissociative ionization of D2 molecules induced by electron impact. Cross sections are determined in the molecular frame and are fully differential in the energies and emission angles of the dissociation fragments. Transitions are considered from the X1Σg+ electronic ground state of D2 to the 2sσg, 2pπu and 2pσu excited states of D2+. The experimental results are compared to calculations performed within the molecular four-body distorted-wave framework to describe the multicenter nature of the scattering process. The cross sections …
Low-Energy Electron-Impact Ionization Of Argon: Three-Dimensional Cross Section, Xueguang Ren, Thomas Pfluger, Joachim Hermann Ullrich, Oleg I. Zatsarinny, Klaus Bartschat, Don H. Madison, Alexander Dorn
Low-Energy Electron-Impact Ionization Of Argon: Three-Dimensional Cross Section, Xueguang Ren, Thomas Pfluger, Joachim Hermann Ullrich, Oleg I. Zatsarinny, Klaus Bartschat, Don H. Madison, Alexander Dorn
Physics Faculty Research & Creative Works
Low-energy (E 0 = 70.8 eV) electron-impact single ionization of a 3p electron in argon has been studied experimentally and theoretically. Our measurements are performed using the so-called reaction microscope technique, which can cover nearly a full 4π solid angle for the emission of a secondary electron with energy below 15 eV and projectile scattering angles ranging from -8° to -30°. The measured cross sections are internormalized across all scattering angles and ejected energies. Several theoretical models were employed to predict the triple-differential cross sections (TDCSs). They include a standard distorted-wave Born approximation (DWBA), a modified version to account for …
Differential Cross Sections For Single Ionization Of H₂ By 75kev Proton Impact, Ujjal Chowdhury, Michael Schulz, Don H. Madison
Differential Cross Sections For Single Ionization Of H₂ By 75kev Proton Impact, Ujjal Chowdhury, Michael Schulz, Don H. Madison
Physics Faculty Research & Creative Works
We have calculated Triply differential cross sections (TDCS) and doubly differential cross sections (DDCS) for single ionization of H2 by 75 keV proton impact using the molecular 3 body distorted wave Eikonal initial state (M3DW-EIS) approach. Previously published measured DDCS-P (differential in the projectile scattering angle and integrated over the ejected electron angles) found pronounced structures at relatively large angles which were interpreted as an interference resulting from the two-centered potential of the molecule.
Low Energy (E,2e) Studies From Ch₄: Results From Symmetric Coplanar Experiments And Molecular Three-Body Distorted Wave Theory, Kate L. Nixon, Andrew James Murray, Hari Chaluvadi, Chuangang Ning, Don H. Madison
Low Energy (E,2e) Studies From Ch₄: Results From Symmetric Coplanar Experiments And Molecular Three-Body Distorted Wave Theory, Kate L. Nixon, Andrew James Murray, Hari Chaluvadi, Chuangang Ning, Don H. Madison
Physics Faculty Research & Creative Works
Low energy experimental and theoretical triply differential cross sections are presented for electron impact ionization of methane (CH4) for both the highest occupied molecular orbital (HOMO) and next highest occupied molecular orbital (NHOMO). The HOMO is a predominantly p-type orbital which is labeled 1t2 and the NHOMO is predominantly s-type labeled 2a 1. Coplanar symmetric (symmetric both in final state electron energies and observation angles) are presented for final state electron energies ranging from 2.5 to 20 eV. The theoretical M3DW (molecular three-body distorted wave) results are in surprisingly good agreement with experiment for the HOMO …
Differential Cross Sections For Single Ionization Of H₂ By 75-Kev Proton Impact, Ujjal Chowdhury, Michael Schulz, Don H. Madison
Differential Cross Sections For Single Ionization Of H₂ By 75-Kev Proton Impact, Ujjal Chowdhury, Michael Schulz, Don H. Madison
Physics Faculty Research & Creative Works
We have calculated triply differential cross sections (TDCS) and doubly differential cross sections (DDCS) for single ionization of H2 by 75-keV proton impact using the molecular three-body distorted-wave-eikonal initial-state (M3DW-EIS) approach. Previously published measured DDCS (differential in the projectile scattering angle and integrated over the ejected electron angles) found pronounced structures at relatively large angles that were interpreted as an interference resulting from the two-centered potential of the molecule. Theory treating H2 as atomic H multiplied by a molecular interference factor only predicts the observed structure when assumptions are made about the molecular orientation. Here we apply the …
Dynamical (E, 2e) Studies Using Tetrahydrofuran As A Dna Analogue, Christopher J. Colyer, Susan M. Bellm, G. Friedrich Hanne, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning, B. Lohmann
Dynamical (E, 2e) Studies Using Tetrahydrofuran As A Dna Analogue, Christopher J. Colyer, Susan M. Bellm, G. Friedrich Hanne, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning, B. Lohmann
Physics Faculty Research & Creative Works
We present dynamical (e, 2e) measurements for the electron impact ionization of formic acid and tetrahydrofuran molecules performed under similar kinematics. The experiments have been performed in the coplanar asymmetric geometry for a range of momentum transfers, at an incident electron energy of 250 eV and with an ejected electron energy of 10eV. The experimental results are compared with theoretical calculations carried out using the molecular 3-body distorted wave (M3DW) model.
Recent Theoretical Progress In Treating Electron Impact Ionization Of Molecules, Ola A. Al-Hagan, Chuangang Ning, Kate L. Nixon, Andrew James Murray, Christopher J. Colyer, Mark A. Stevenson, B. Lohmann, Don H. Madison
Recent Theoretical Progress In Treating Electron Impact Ionization Of Molecules, Ola A. Al-Hagan, Chuangang Ning, Kate L. Nixon, Andrew James Murray, Christopher J. Colyer, Mark A. Stevenson, B. Lohmann, Don H. Madison
Physics Faculty Research & Creative Works
(e,2e) ionization differential cross sections are presented for several molecules. We will compare experimental results with theoretical calculations using the molecular three body distorted wave (M3DW) approximations for H 2, N2, H2O and Formic Acid (FA) using better wave-function for the molecules than we had in previous works. Generally, good agreement is found between the M3DW approach and experiments.