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Physical Sciences and Mathematics Commons

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Physics Faculty Research & Creative Works

Helium

2012

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Four Body Charge Transfer Process In Proton Helium Collision, Ujjal Chowdhury, Allison L. Harris, Jerry Peacher, Don H. Madison Jul 2012

Four Body Charge Transfer Process In Proton Helium Collision, Ujjal Chowdhury, Allison L. Harris, Jerry Peacher, Don H. Madison

Physics Faculty Research & Creative Works

Recent advancements in experimental techniques now allow for the study of fully differential cross sections for 4-body collisions. Theoretical fully differential cross sections will be presented and compared with absolute experimental data for transfer-excitation in proton-helium collisions. The role of different scattering mechanism will be discussed.


Fully Differential Cross Section For Four Body Charge Transfer Process, Ujjal Chowdhury, Allison L. Harris, Jerry Peacher, Don H. Madison Jul 2012

Fully Differential Cross Section For Four Body Charge Transfer Process, Ujjal Chowdhury, Allison L. Harris, Jerry Peacher, Don H. Madison

Physics Faculty Research & Creative Works

Recently experimental fully differential cross sections (FDCS) have been reported for double capture in proton helium collisions which disagree with existing theoretical calculations by two orders of magnitude. We introduce here a theoretical model for charge transfer processes which is fully quantum mechanical and takes all post collision interactions (PCI) between the particles into account exactly. The results of this model are in much better agreement with experimental data.


Strongly Enhanced Backward Emission Of Electrons In Transfer And Ionization, Michael Schulz, Xincheng Wang, M. Gundmundsson, Katharina R. Schneider, Aditya H. Kelkar, Alexander B. Voitkiv, B. Najjari, Markus S. Schoffler, Lothar Ph H H Schmidt, Reinhard Dorner, Joachim Hermann Ullrich, Robert Moshammer, Daniel Fischer Jan 2012

Strongly Enhanced Backward Emission Of Electrons In Transfer And Ionization, Michael Schulz, Xincheng Wang, M. Gundmundsson, Katharina R. Schneider, Aditya H. Kelkar, Alexander B. Voitkiv, B. Najjari, Markus S. Schoffler, Lothar Ph H H Schmidt, Reinhard Dorner, Joachim Hermann Ullrich, Robert Moshammer, Daniel Fischer

Physics Faculty Research & Creative Works

We studied three-dimensional angular distributions and longitudinal momentum spectra of electrons ejected in transfer plus ionization (TI), i.e., the ejection of one and the capture of a second target electron, for ion-helium collisions. We observe a pronounced structure strongly focused opposite to the projectile beam direction, which we associate with a new correlated TI mechanism proposed recently. This process contributes significantly to the total cross sections over a broad range of perturbations η, even at η as large as 0.5, where uncorrelated TI mechanisms were thought to be dominant.