DIAGNOSTICS OF PICOSECOND LASER-PULSES USING NONLINEAR FORCES OF PONDEROMOTIVE DYNAMICS

Experiments on electron acceleration by lasers in vacuum have shown th at the approximate description of the acceleration by a ponderomotive potential can be extended to a quiver drift description, This more gen eral description is necessary when the general non-linear forces no lo nger permit a conservative ponderomotive potential. One consequence is that for the simplified conditions of the interaction of an electron beam with a laser beam a modification results in which the electron en ergy is up or down shifted due to the stochastic phase variation durin g interaction, Further, an axial displacement of the electron is deriv ed which can be applied to analyse the filamentation (hot spot) proper ties of picosecond or shorter laser pulses.