Electron acceleration by amplified wakefield generated by two copropagating laser pulses in plasma

A detailed analytical theory is developed for studying the phenomenon of generation of high amplitude wakefield using a seed laser pulse and another coaxially propagating, trailing pulse. The two laser pulses are separated by a fixed distance between them and have the same polarization, frequency, length, intensity, and profile. The study shows that the maximum energy gained by the test electron significantly depends upon the distance between the two pulses. Phase space analysis shows that a test electron of significantly lower energy, injected behind the trailing laser pulse, will be trapped and accelerated to higher energy as compared to the single pulse case.