Crossed-beam energy transfer in implosion experiments on OMEGA

Radiative hydrodynamic simulations of implosion experiments on the OMEGA laser system [Boehly et al. , Opt. Commun. 133, 495 (1997)] show that energy transfer between crossing laser beams can reduce laser absorption by 10%–20%. A new quantitative model for the crossed-beam energy transfer has been developed, allowing one to simulate the coupling of multiple beams in the expanding corona of implosion targets. Scattered-light and bang-time measurements show good agreement with predictions of this model when nonlocal heat transport is employed. The laser absorption can be increased by narrowing laser beams and/or employing two-color light, which both reduce the crossed-beam energy transfer.