A NEW LAGRANGIAN FORMULATION FOR LASER-PLASMA INTERACTIONS

A new Lagrangian structure for cold relativistic plasma electrodynamic s is presented. This new formulation uses the fluid velocity v instead of the canonical-momentum Clebsch potential psi [X. L. Chen and R. N. Sudan, Phys. Fluids B 5, 1336 (1993)], As a simple application, it is used to derive (through the Noether method) new exact conservation la ws associated with nonlinear laser wake-field equations in the multi-d imensional quasi-static approximation. (C) 1998 American Institute of Physics.