Energy and polarization exchange during simultaneous interactions between many laser beams in plasmas

ICF and HED experiments at the National Ignition Facility (NIF) typically involve simultaneous interactions between 96 laser beams overlapping in the same volume of hot plasma, at the entrance of “hohlraum” targets. It has been shown [1] that such interactions can not only lead to energy exchange between beams (depending on their relative frequencies and the presence of Doppler shifts from plasma flows), but also affect the polarizations of the lasers. We investigate new methods to calculate the simultaneous interactions of multiple beams coupled via pair-wise, ponderomotively-driven density modulations (4560 pair-wise couplings for 96 beams). We will present simulation algorithms, conservation laws, and discuss implications for light propagation and laser-plasma interactions in ICF experiments at NIF.

[1] P. Michel et al., Phys. Rev. Lett. 113, 205001 (2014).