Multiorbital tunneling ionization of the CO molecule

We coincidently measure the molecular frame photoelectron angular distribution and the ion sum-momentum distribution of single and double ionization of CO molecules by using circularly and elliptically polarized femtosecond laser pulses, respectively. The orientation dependent ionization rates for various kinetic energy releases allow us to individually identify the ionizations of multiple orbitals, ranging from the highest occupied to the next two lower-lying molecular orbitals for various channels observed in our experiments. Not only the emission of a single electron, but also the sequential tunneling dynamics of two electrons from multiple orbitals are traced step by step. Our results confirm that the shape of the ionizing orbitals determine the strong laser field tunneling ionization in the CO molecule, whereas the linear Stark effect plays a minor role.Comment: This paper has been accepted for publication by Physical Review Letter

Three-body Interactions In Proton-helium Angular Scattering

H++He scattering at 0.5 MeV has been investigated using a coincidence technique that completely determines the three-body transverse momentum exchange in single ionization collisions. Three scattering regions could be distinctly recognized that are dominated by proton helium-nucleus, proton-electron, or electron helium-nucleus interactions. Calculations and the experimental data show that the coupling between the electronic and nuclear degrees of freedom is required to understand the dynamics for more than 97% of the ionizing collisions. © 1989 The American Physical Society

Regimes of cosmic-ray diffusion in Galactic turbulence

Cosmic-ray transport in astrophysical environments is often dominated by the diffusion of particles in a magnetic field composed of both a turbulent and a mean component. This process, which is two-fold turbulent mixing in that the particle motion is stochastic with respect to the field lines, needs to be understood in order to properly model cosmic-ray signatures. One of the most important aspects in the modeling of cosmic-ray diffusion is that fully resonant scattering, the most effective such process, is only possible if the wave spectrum covers the entire range of propagation angles. By taking the wave spectrum boundaries into account, we quantify cosmic-ray diffusion parallel and perpendicular to the guide field direction at turbulence levels above 5% of the total magnetic field. We apply our results of the parallel and perpendicular diffusion coefficient to the Milky Way. We show that simple purely diffusive transport is in conflict with observations of the inner Galaxy, but that just by taking a Galactic wind into account, data can be matched in the central 5 kpc zone. Further comparison shows that the outer Galaxy at &gt; 5 kpc, on the other hand, should be dominated by perpendicular diffusion, likely changing to parallel diffusion at the outermost radii of the Milky Way.</p

\u3ci\u3eCivil Society, Conflict and Violence\u3c/i\u3e

Editors: Wolfgang Dörner and Regina A. List Chapter 6, The Law, Security and Civil Society Freedoms, co-authored by Brett Kyle, UNO faculty member. This book looks at the role that civil society organizations play in dealing with conflict and violence. The authors argue that in most of the prevalent conceptualizations the conflict dimension of civil society is either downplayed or inadequately addressed. They contend that the ability to deal with conflict is at the heart of organized civil society; in the political process, one of civil society\u27s key functions is to express and mediate between different interests, thus contributing to political decision-making. The chapters draw on detailed, empirical data from the CIVICUS Civil Society Index - a unique comparative data-set drawn from 25 countries, which has not previously been made publicly available. It examines the different ways violence has been manifested in civil societies, the meaning of violent protest and the impact of security legislation that might hinder the mediating efforts of civil society. The book offers a sophisticated comparison between conflict and post-conflict countries and an analysis of the role of civil society in conflict resolution, reconciliation and transitional justice.https://digitalcommons.unomaha.edu/facultybooks/1307/thumbnail.jp

Transfer ionization and its sensitivity to the ground-state wave function

We present kinematically complete theoretical calculations and experiments for transfer ionization in H$^++$He collisions at 630 keV/u. Experiment and theory are compared on the most detailed level of fully differential cross sections in the momentum space. This allows us to unambiguously identify contributions from the shake-off and two-step-2 mechanisms of the reaction. It is shown that the simultaneous electron transfer and ionization is highly sensitive to the quality of a trial initial-state wave function