The Chirped-pulse Inverse Free-electron Laser

We propose a new accelerating concept, the chirpedpulse inverse free-electron laser (CPIFEL). We study the inverse free-electron laser (IFEL) accelerator both theoretically and computationally, and show that by using a femtosecond (fs), ultra-high-intensity drive laser pulse, the IFEL interaction bandwidth and accelerating gradient are increased, thus yielding large energy gains. Using a chirped pulse and negative dispersion focusing optics allows one to take advantage of the laser bandwidth and produce a chromatic line focus, maximizing the gradient. Combining these ideas results in a compact vacuum laser accelerator capable of accelerating picosecond (ps) electron bunches with a high gradient (GeV/m) and very low energy spread.