Effects of ponderomotive forces and space-charge field on laser plasma hydrodynamics

Using a two-fluid two-temperature hydrodynamic code, we studied the hydrodynamics in the interaction of intense (10(15) W/cm(2)) ultrashort (150fs) laser pulses and linear density plasmas. The simulation results show the ponderomotive force effect on the formation of the electron density ripples in underdense region, such ripples increase the reflection of the laser pulse, and on the separation of the plasma in critical surface. Quasi-electroneutrality is not suitable in this case because of the different ponderomotive force and the gradient of thermal-pressure for ions and electrons. Ions are moved by the electrostatic force. Comparing with the simulation results from one-fluid two-temperature code, we find that under strong ponderomotive force and gradient of thermo-pressure, two-fluid code is more suitable to simulate the hydrodynamics of plasmas.