Research Article

Direct Laser-Driven Electron Acceleration and Energy Gain in Helical Beams

Figure 6

Lasers with  fs pulse duration and beam waist radius. The full and dotted lines correspond to a CP and LP laser of  PW power, with red, blue, and black, respectively. (a0) The time evolution of the mean net energy gain of electrons; (b0) the time evolution of the highest energy electron, ; both correspond to Gaussian pulses of different powers and polarizations. (a1, b1) The energy gains corresponding to the helical beam, (a2, b2) and (a3, b3) helical beams, and (a4, b4) and (a5, b5) helical beams.