Electrons in Strong Fields Generated by Atomic Systems and Lasers
Final Report Abstract
This project aimed at the theoretical exploration of a number of important aspects of the behaviour of electrons in relativistic collisions of highly charged ions with atoms and in the combined field of a highly charged nucleus and a very intense laser field. Concerning the part on ion-atom collisions, the main achievements of the project are the following. We have proposed two models for projectile-electron excitation and loss: one of them for collisions with many-electron atoms at intermediately large impact energies, where both the screening of the atomic nucleus by atomic electrons and higher order contributions in the interaction with the atom should be taken into account, and the other one for collisions with light atoms at large momentum transfers. The description of two-electron transitions in the projectile ion was also addressed using the relativistic symmetric eikonal model. A highly correlated process of transfer ionization in fast (including relativistic) collisions with highly charged ions was explored and novel effects were predicted. In the part on the electron motion in the fields of a highly charged ion and a strong laser field the main results include the extensions of theories of laser-assisted inelastic electron-ion scattering and radiative electron recombination in a laser field to the relativistic domain. We also found an approximate analytic solution describing the motion of a relativistic electron under the simultaneous action of the Coulomb and laser fields which becomes exact when the Coulomb field is generated by a charged particle moving with the speed of light. During the work on the project we obtained some quite unexpected results with two of them as follows. First, despite the huge difference in mass (and thus impact energy) between electrons and protons, it turned out that electrons can be much more effective in producing excitations of very highly charged ions than equi-velocity protons. Second, in the field of fast ion-atom collisions it has been taken for granted that large transverse momentum transfers correspond to collisions with small impact parameters and vice versa. Such a correspondence, however, completely vanishes when one considers the Coulomb corrections (higher-order contributions) in ultra-relativistic collisions: these corrections come from collisions with very small impact parameters and, simultaneously, from collisions with extremely small transverse momentum transfers.
Publications
- Inelastic Collisions of Relativistic Electrons with Atomic Targets in a Laser Field. Phys. Rev. Lett. 103, 193201 (2009)
A. B. Voitkiv, B. Najjari, and J. Ullrich
- Relativistic electron-ion recombination in the presence of an intense laser field. J. Phys. B 42, 221001 (2009)
C Müller, A B Voitkiv and B Najjari
- Bound-bound pair production in relativistic collisions. New Journal of Physics 12, 063011 (2010)
A. B. Voitkiv, B. Najjari and A. DiPiazza
- Symmetric eikonal model for projectile-electron excitation and loss in relativistic ion-atom collisions. Phys. Rev. A 82, 022707 (2010)
A. B. Voitkiv, B. Najjari, and V. P. Shevelko
- Young-type interference in projectile-electron loss in energetic ion-molecule collisions. Phys. Rev. Lett. 106, 233202 (2011)
A.B. Voitkiv, B. Najjari, D. Fischer, A. Artemyev, and A. Surzhykov
- Excitation of heavy hydrogenlike ions by light atoms in relativistic collisions with large momentum transfers. Phys. Rev. A 85, 052712 (2012)
A.B. Voitkiv and B. Najjari
(See online at https://doi.org/10.1103/PhysRevA.85.052712) - lectron Loss, Excitation, and Pair Production in Relativistic Collisions of Heavy Atomic Particles. In V. Shevelko (Ed.), Atomic Processes in Basic and Applied Physics (pp. 153-183). Berlin Heidelberg: Springer (2012)
A.B. Voitkiv and B. Najjari
- Excitation of highly charged hydrogenlike ions by the impact of equivelocity electrons and protons: A comparative study. Phys. Rev. A 87, 034701 (2013)
A.B. Voitkiv and B. Najjari
(See online at https://doi.org/10.1103/PhysRevA.87.034701) - Transfer Ionization in Collisions with a Fast Highly Charged Ion
A.B. Voitkiv
(See online at https://doi.org/10.1103/PhysRevLett.111.043201) - Relativistic transfer ionization and the Breit interaction. Phys. Rev. Lett. 112, 103202 (2014)
Yu. Andreev, E. A. Mistonova and A. B. Voitkiv
(See online at https://doi.org/10.1103/PhysRevLett.112.103202)
