Marius Stroe

Dissociative excitation in electron collisions with HD

In the framework of the multi-channel quantum defect theory (MQDT), we have performed nonrotational computations for the dissociative excitation cross section of HD+ initially in the vibrational level vi+ (vi+=0, vi+=1 or vi+=2) of the electronic ground state, with electrons of energy ranging from 2 to 12 eV. Considering the case of energy-independent interactions, the reaction matrix K is evaluated in the second order of the Born expansion of the Lippmann–Schwinger equation.

Electron-induced processes in H+2, D+2 and T+2

We investigate the isotopic effects on the cross sections of the dissociative excitation, dissociative recombination, vibrational excitation and vibrational de-excitation of the homonuclear hydrogen molecular cations with electrons of energy above the dissociation threshold of the electronic ground state. The computations were accomplished using an improved numerical code based on a previous work (Fifirig and Stroe 2008 Phys. Scr. 78 065302).

Dissociation of vibrationally excited by electrons

We have investigated the electron impact dissociation of the deuterium molecular cation assuming a Franck–Condon distribution of the initial vibrational states given by electron impact ionisation of D2. The electron energy range 1–12 eV has been considered. The relative contributions of the initial vibrational states to the total cross-sections of the dissociative recombination and excitation have been determined.

Resonances and antibound states for the dressed one-dimensional δ-function potential

We calculate resonances, antibound states and two new light induced states of the dressed one-dimensional attractive δ-function potential, as function of α0 — the free electron quiver motion amplitude in a monochromatic electromagnetic field, in the range 0<α0<150 a.u. We describe also our method, adequate to the numerical solution of the Schrodinger equation for this particular potential.

Electron impact on vibrationally cold

The dissociative recombination and vibrational excitation processes induced by electron impact on vibrationally cold are investigated in the framework of the multichannel quantum defect theory for electron energies below 1 eV. The thermal rate coefficients for the electron temperature range from 10 to 5000 K are reported.

Dissociation of H+2 ions by collisions with electrons

We have studied the electron impact dissociation of vibrationally excited H+2. A distribution of initial vibrational states given by the overlap factors between the vibrational ground state of H2 and different vibrational levels of H+2 has been considered. It was found that the relative contributions of the initial vibrational levels to the dissociative excitation cross section mimic the vibrational distribution of the H+2 molecular ion for electron energies larger than the energy difference between the energy of the repulsive state 2Σ+u and that of the lowest vibrational level of the ground state X2Σ+g at the outer classical turning point.

Phase- and helicity-dependent effects in three-color ionization

We study the two-photon ionization of the hydrogen atom from its ground state by a three-color electromagnetic field consisting of a superposition of an IR laser and two of its consecutive odd harmonics of order 2p−1 and 2p+1, withp a positive integer and constant relative phase difference. The ionization process due to the net absorption of the energy 2pħω (ω being the IR laser frequency) is considered. The influence of phase difference and helicity on the azimuthal angular distribution of the ejected photoelectrons is illustrated in the case in which the two harmonics have identical polarizations. Phase effect on the alignment of the differential ionization rate is also investigated.