EPL, 77 (2007) 64004
DOI: 10.1209/0295-5075/77/64004

Refocussed relativistic recollisions

M. Verschl and C. H. Keitel

Max-Planck-Institut für Kernphysik - Saupfercheckweg 1, 69117 Heidelberg, Germany

received 8 November 2006; accepted in final form 2 February 2007; published March 2007
published online 5 March 2007

Abstract
It is demonstrated that a magnetic field pulse can be applied to refocus a spreading electron wave packet in a relativistic recollision scheme. The drift due to the Lorentz force occurring in strong laser fields is employed to separate an electron from the core. Before it is driven back for recollision by a second counter-propagating laser pulse, the dynamics of wave packet spreading is reversed by a magnetic field pulse. At the instant of recollision, the electron wave packet is refocussed to small spatial widths while it holds maximal kinetic energy. This way, efficient recollisions are shown to occur up to the high-energy regime.

PACS
41.75.Jv - Laser-driven acceleration.
34.80.Kw - Electron-ion scattering; excitation and ionization.
41.75.Ht - Relativistic electron and positron beams.

© Europhysics Letters Association 2007