LASER ACCELERATION OF CHARGED-PARTICLES IN INHOMOGENEOUS PLASMAS .1.

The interaction of a laser pulse with a thin high-density plasma slab (foil) is proposed as a mechanism for producing laser pulses with the appropriate shape (sharp leading and/or rear edges). Such a pulse is o ptimum for the excitation of high-amplitude wake fields in underdense plasmas. It is shown (analytically and via particle-in-cell numerical simulations) that a phase-stable regime of unlimited particle accelera tion can be realized in inhomogeneous plasmas.