Laser acceleration of proton bunches by petawatt chirped linearly polarized laser pulses

Detailed single- and many-particle calculations are carried out for the acceleration of protons employing linearly polarized plane-wave and tightly focused chirped laser pulses of several ten to several hundred femtosecond durations, petawatt peak powers, and relativistic peak intensities. Analytic and numerical methods of calculation are used in the single-particle cases (in vacuum), and particle-in-cell (PIC) simulations (underdense plasma) are employed in the many-particle investigations, without and with electromagnetic particle-particle interactions, respectively. The investigations cover a wide range of cases corresponding to upchirped as well as downchirped pulses.