Induced electrostatic fields in dense plasmas with an intense ultrashort pulse laser

The electrostatic fields induced by an intense laser field around an ion in a solid density plasma are investigated. In a plasma produced by irradiating an intense ultrashort pulse laser on a solid target, the electron and ion temperatures are not in thermal equilibrium, and the electron temperature is higher than the ion temperature. For such a plasma, the dynamical form factor of a plasma electron is derived. By using the dynamical form factor, the screened potential and the induced oscillating electrostatic field around an ion are obtained. As a result, the plasma screening effects on the direct ionization by the laser are clarified.