Monoenergetic electron bunches generated from thin solid foils irradiated by ultrashort, ultraintense circularly polarized lasers

Future ultrashort 10^{22}–10^{25} W cm^{-2} laser pulses offer the possibility of producing ultrashort monoenergetic electron beams in the GeV–TeV level by direct laser ponderomotive force acceleration (LPFA) in distances of millimeters to about 1 m. A scheme is proposed that a thin solid foil and a thick solid foil are placed on the laser axis, where the thin foil supplies the electron source for LPFA and the thick foil reflects the laser away, however allows the accelerated electrons to go through. By optimizing the distance between the foils, one can obtain the maximum electron beam energy. This scheme is demonstrated by particle-in-cell simulations.