Vibrational Excitation Cross-Section by Positron Impact: A Wave-Packet Dynamics Study

Comparison of positron-impact vibrational excitation cross sections with the Born-dipole model

The development of cold trap-based positron beams and new scattering techniques has recently enabled the first measurements of state-resolved positron-impact vibrational excitation cross sections. These measurements revealed a number of features worth further consideration, such as relatively sharp increases near threshold. This paper describes a comparison of the magnitudes and shapes of these...

Vibrational excitation of water by electron impact

Experimental and calculated differential cross sections DCSs for electron-impact excitation of the 010 bending mode and unresolved 100 symmetric and 001 antisymmetric stretching modes of water are presented. Measurements are reported at incident energies of 1–100 eV and scattering angles of 10° –130° and are normalized to the elastic-scattering DCSs for water determined earlier by our group. Th...

Excitation of molecular vibrations by positron impact.

Absolute cross sections for the vibrational excitation of CO, CO2, and H2 by positron impact are presented for incident positron energies from 0.5 eV to several electron volts. The measurements use a novel technique that exploits the adiabatic motion of a positron beam in a strong magnetic field. This work is the first systematic experimental study of vibrational excitation by positron impact, ...

Electron Impact Vibrational Excitation Cross Sections of SiF4

Wave-packet dynamics by optimized polynomials methods

An optimized and numerically stable method, based on the formalism of orthogonal polynomials, is proposed to solve the time-dependent Schrödinger equation and to construct energy-filtered wave-packets. It is compared to other methods (Runge-Kutta, Second-Order Differencing scheme). A method is also devised to study quantum diffusion in finite systems with periodic boundary conditions, which all...