Wakefield generation in one-dimensional LWFA

The generation of wakefields in near-critical density plasma by a short las er pulse is considered. The equations describing the plasma response to the acting laser pulse and the Hamiltonian of an electron in the wakefield are derived by using the Hamilton-Jacobi equation for the cases of nu (g) simi lar or equal to nu (p) similar or equal to w = c w < c (e is the speed of l ight). The equations are solved analytically in two cases for a square-shap ed laser pulse. The plasma potential inside the laser pulse and the wakefie ld potential excited by the laser pulse are obtained. The optimal length of the driving laser pulse and the wavelength of the wake are expressed by th e group velocity.