A. I. Bondarev

Electron-positron pair creation in low-energy collisions of heavy bare nuclei

A new method for calculations of electron-positron pair-creation probabilities in low-energy heavy-ion collisions is developed. The approach is based on the propagation of all one-electron states via the numerical solving of the time-dependent Dirac equation in the monopole approximation. The electron wave functions are represented as finite sums of basis functions constructed from B-splines using the dual-kinetic-balance technique. The calculations of the created particle numbers and the positron energy spectra are performed for the collisions of bare nuclei at the energies near the Coulomb barrier with the Rutherford trajectory and for different values of the nuclear charge and the impact parameter. To examine the role of the spontaneous pair creation the collisions with a modified velocity and with a time delay are also considered. The obtained results are compared with the previous calculations and the possibility of observation of the spontaneous pair creation is discussed.

Relativistic calculations of theK-Kcharge transfer andK-vacancy production probabilities in low-energy ion-atom collisions

The previously developed technique for evaluation of charge-transfer and electron-excitation processes in low-energy heavy-ion collisions [I.I. Tupitsyn et al., Phys. Rev. A 82, 042701(2010)] is extended to collisions of ions with neutral atoms. The method employs the active electron approximation, in which only the active electron participates in the charge transfer and excitation processes while the passive electrons provide the screening DFT potential. The time-dependent Dirac wave function of the active electron is represented as a linear combination of atomic-like Dirac-Fock-Sturm orbitals, localized at the ions (atoms). The screening DFT potential is calculated using the overlapping densities of each ions (atoms), derived from the atomic orbitals of the passive electrons. The atomic orbitals are generated by solving numerically the one-center Dirac-Fock and Dirac-Fock-Sturm equations by means of a finite-difference approach with the potential taken as the sum of the exact reference ion (atom) Dirac-Fock potential and of the Coulomb potential from the other ion within the monopole approximation. The method developed is used to calculate the K-K charge transfer and K-vacancy production probabilties for the Ne

Quantum Electrodynamics Effects in Heavy Ions and Atoms

(1s^2 2s^2 2p^6)

Ionization probabilities in low-energy heavy-ion collisions

-- F

Relativistic calculations of differential ionization cross sections: Application to antiproton-hydrogen collisions

^{8+}(1s)

Contribution of higher multipole terms of Coulomb interaction to ionization in low-energy heavy-ion collisions

collisions at the F

Relativistic calculations of the U91+(1s)–U92+ collision using the finite basis set of cubic Hermite splines on a lattice in coordinate space

^{8+}(1s)

One-center calculations of the electron-positron pair creation in low-energy collisions of heavy bare nuclei

projectile energies 130 keV/u and 230 keV/u. The obtained results are compared with experimental data and other theoretical calculations. The K-K charge transfer and K-vacancy production probabilities are also calculated for the Xe -- Xe

Electron-positron pair creation in collisions of heavy bare nuclei: One-center approach

^{53+}(1s)

Relativistic calculations of excitation and ionization probabilities in highly charged H-like ions exposed to intense laser fields

collision.