GeV-acceleration of electron by a superintense ultrashort laser pulse

✍ Scribed by A. Bahari; V.D. Taranukhin

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 161 KB
• Volume: 1
• Category: Article
• ISSN: 1612-2011
• DOI: 10.1002/lapl.200410089

✦ Synopsis

New mechanism of laser acceleration of a charged
particle is discovered and explained. Particle acceleration with
focused beam of superintense ultrashort laser pulse is determined
by a combination of ponderomotive forces at rising and falling
edges of laser pulse and a longitudinal component of laser
electric field. We found that acceleration of electron, which
moves along the laser wavevector, is crucially depends on whether
or not the electron reaches the region z ⩾ z
~R~ behind the
laser focus (here z
~R~ is the Rayleigh length). Interpretation
of this effect consists in that the laser longitudinal electric
field at the electron trajectory in this region is a
unidirectional one (oscillatory in the case of laser linear
polarization and slowly varying in the case of laser circular
polarization). Due to this effect it is possible to overcome the
negative influence of a phase slippage in the particle-wave
interaction, which substantially suppresses electron acceleration.
We revealed also that the physical reason of a unidirectional
influence of laser longitudinal electric field on accelerating
electron in the region z ⩾ z
~R~ consists in the difference
in phase velocities of transverse and longitudinal components of a
focused laser field. Owing to this mechanism, lasers of ultimate
present-day parameters enable electron acceleration up to the
energy ε ≃ 1 GeV. Moreover, electron
acceleration along the laser wavevector (in contrast to techniques
currently considered) is not sensitive to field initial phase
(there is no bunch effect), it is possible to accelerate slow
electrons (electrons need not to be preaccelerated to relativistic
velocities), and there are no problems with a removal of
accelerated electron from the laser field.