Hot Electron Acceleration In The Process Of Ultra-intense And Ultra-short Laser Plasmas Interaction

The study of ultra-intense and ultra-short laser interacting with plasmas on the acceleration of hot electrons is relevant to a wide range of important applications, and it tempted many people to explore it continually. We take advantage of electron distribution function to discuss the production and distribution of hot electrons, taking account of Gaussian laser pulse.We analyze fully electron trajectory under the action of various ultra-intense and ultra-short laser in this paper. For the plane wave of laser without pulse shape, we derive the express of electron trajectory by the relative Lorentz and energy equations. Note that the orbit of electron becomes a "fat-8" in the average rest frame. For the plane wave of Gaussian laser, we may know that, through relative Hamilton-Jacobi equation, electrons are accelerated in the front of pulse and decelerated backward. Whereas for the non-plane wave of Gaussian laser, we solve the Lorentz and energy equations by fourth order Runge-Kutta method. Note that electrons are accelerated continually by longitudinal ponderomotive force and radial electric force. For a high laser intensity and small spot size, an electron may escape from the laser and can retain energy gain.We obtain analytical expresses of electron instantaneous momentum. Taking the plane wave of Gaussian laser for an example, we derive electron distribution function over instantaneous values of electron momentum and energy. If the initial temperature of electron is not high (about100eV) and the length of laser pulse is very short (about 4-6 laser wavelength), this paper also can obtain double hot-electron peak and the temperature of electron can larger than 1 MeV. if the length of laser pulse is extremely short (about 2-3 laser wavelength) and the initial temperature of electrons is not high, there...