Laser crossing-beam energy transfer model based on ray-tracing method

A new ray-based model of crossing-beam energy transfer (CBET) is developed. This model can be used in dynamic kinetic codes for evaluating CBET in line. By defining laser intensity in grid through inverse bremsstrahlung absorption formula of laser, every single ray of probe laser beam can obtain (or lose) energy from the intensity of pump laser beam. Since CBET is dependent on the history of every single laser ray and the coupling between probe laser and pump laser is strong, the coupling equations are difficult to be solved. Calculating iteratively can solve the problem well. This in-line CBET model can be generalized to the situation where there are energy transfers among three or more laser beams easily. Inverse bremsstrahlung absorption and laser plasma interaction could also be involved in the model.