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Center for Nonlinear Studies |
In this talk we discuss single ionization in laser-assisted high-energy non-relativistic ion-atom collisions. We show that the low-energy angular differential electron spectrum may be enhanced significantly by a weak, in atomic terms, external laser-field. With increasing the strength of this assisting field, the electron spectrum develops a plateau with a characteristic cut-off [1]. In the plateau region we predict distinct multiphoton peaks separated by the photon-energy. Within the present laser-assisted continuum-distorted-wave eikonal-initial-state (LA-CDW-EIS) theory, this effect can be easily traced out and may be related to the dynamics in the two-body electron-projectile subsystem. Other first order approximation theories, e.g. the laser-assisted distorted wave Born (LA-DWB) [2] and first Born approximation (LA-FBA) [3], do not account for the phase-distortion of the target electron by the incoming projectile and consequently the associated plateau, cut-off and multiphoton features are not predicted by these approaches. The combined process where an electron is ionized by a heavy ion and subsequently moves in the laser field and under the influence of the Coulomb fields of the projectile and the target represents a stringent test for distorted wave theories.
References
[1] M. F. Ciappina and L. B. Madsen,, Phys. Rev. A 77 023412 (2008).
[2] M. F. Ciappina and L. B. Madsen, J. Phys. B 39 5037 (2006).
[3] A. Voitkiv and J. Ullrich, J. Phys. B 34 1673 (2001); ibid, J. Phys. B
34 4383 (2001).h
Host: James Colgan, T-04