A modification of the PIC method with adaptive mass: the interaction of a laser pulse and a plasma

A modification of the PIC method with adaptive mass is proposed. This modification allows one to change the particle number dynamically without breaking the conservation laws. The mass and charge of model particles decrease with an increase of their number in low density domains, whereas the mass and charge increase in high density domains. Such a redistribution allows one to reduce the noise in low density domains using a relatively small number of model particles. The work was supported by the Russian Foundation for Basic Research (projects 11-01-00178, 11-01-00249, 12-01-00234, and 12-07-00065).