Acceleration of electrons by lasers in a vacuum was
considered impossible based on the fact that plane-wave
and phase symmetric wave packets cannot transfer energy
to electrons apart from Thomson or Compton scattering or
the Kapitza–Dirac effect. The nonlinear nature of
the electrodynamic forces of the fields to the electrons,
expressed as nonlinear forces including ponderomotion or
the Lorentz force, permits an energy transfer if the conditions
of plane waves in favor of the beams and/or the phase symmetry
are broken. The resulting electron acceleration by lasers
in a vacuum is now well understood as “free wave
acceleration”, as “ponderomotive scattering”,
as “violent acceleration”, or as “vacuum
beat wave acceleration”. The basic understanding
of these phenomena relates to an accuracy principle
of nonlinearity for explaining numerous discrepancies
on the way to the mentioned achievement of “vacuum
laser acceleration”, which goes beyond the well-known
experience of necessary accuracy in both modeling and experimental
work experiences among theorists and experimentalists in
the field of nonlinearity. From mathematically designed
beam conditions, an absolute maximum of electron energy
per laser interaction has been established. It is shown
here how numerical results strongly (both essentially and
gradually) depend on the accuracy of the used laser fields
for which examples are presented and finally tested by
the criterion of the absolute maximum.
In this paper, we extend the work of Barton and Alexander [J. App. Phys. 66, 2800 (1989)] on the fifth-order corrected field expressions for a Hermite-Gaussian (0,0) mode laser beam to more general cases with adjustable parameters. The parametric dependence of the electron dynamics is investigated by numerical methods. Finally, the fifth-order corrected field equations for the Hermite-Gaussian (0,1) mode are also presented.
Troha et al. [Phys. Rev. E 60, 926 (1999)] put forward a generalized Lawson-Woodward theorem in the study of laser accelerations. We point out that one of the assumptions used in their proof does not stand on a solid physical ground and that it is possible for electrons to obtain net energy gains from a plane-wave laser pulse in vacuum even if the radiation reaction effects are neglected.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.