Particle in cell analysis of a laser-cluster interaction including collision and ionization processes

A new particle-in-cell (PIC) code which includes collisional and ionization processes has been developed to study laser-plasma interaction. Using the new code, the dynamics of a cluster plasma in a strong laser field has been analyzed and the threshold intensity of the resonant heating, which was previously predicted is accurately evaluated. The angular dependence of ion energy spectrum has also been simulated. As a result, it is found that the anisotropic energy spectrum depends strongly on the presence or absence of collisional processes.