This paper is a review of low-energy positron interactions with atoms and molecules. Processes of interest include elastic scattering, electronic and vibrational excitation, ionization, positronium formation and annihilation. An overview is presented of the currently available theoretical and experimental techniques to study these phenomena, including the use of trap-based positron beam sources...

The vibrational excitation cross-section of a diatomic molecule by positron impact is obtained using wave-packet propagation techniques. dynamics study was carried on two-dimensional potential energy surface, which couples hydrogenlike harmonic oscillator to via spherically symmetric correlation polarization potential. for the first mode in good agreement with previous reports. Our model sugges...

Positron annihilation rates in many polyatomic molecular gases are anomalously high. Qualitatively, this can be explained by positron capture in vibrational Feshbach resonances, which can occur for molecules with positive positron affinities [Gribakin, Phys. Rev. A 61 (2000) 022720]. To verify this idea quantitatively, we examine the densities of vibrational excitation spectra of alkanes. To un...

The excitation cross-sections of the nS states atomic hydrogen, n = 2 to 6, by electron impact on ground state hydrogen were calculated using variational polarized-orbital method at various incident energies in range 10 122 eV. Converged obtained sixteen partial waves (L 0 15). Excitation 2S state, earlier, higher than before. Results hybrid theory (variational polarized orbital method) are com...

The STAR collaboration at RHIC is measuring the production of electronpositron pairs at small impact parameters, larger than but already close to the range, where the ions interact strongly with each other. We calculate the total cross section, as well as, differential distributions of the pair production process with the electromagnetic excitation of both ions in a semiclassical approach and w...

Domain wall dynamics in thin magnetic films with perpendicular and in-plane anisotropy is studied using a novel magneto-optical Kerr effect susceptometery method. The method allows for measurements of domain wall motion under ac field excitation and the analysis of dynamic modes as a function of driving frequency and magnetic field amplitude. Domain wall dynamics in the perpendicular anisotropy...