Cross-Beam Energy Transfer Platform Development on OMEGA*

A cross-beam energy transfer (CBET) platform was activated on OMEGA. A gas jet was heated by ten 500-ps, 351-nm beams that used phase plates to generate a ~2-mm-diam spherical plasma. Optical Thomson scattering measured a peak temperature of ~700 eV over a uniform ~5 x 10¹⁹ cm–3 electron density plateau of ~1 mm. These results are in good agreement with radiation–hydrodynamics simulations performed by HYDRA. To study CBET, a wavelength‑tunable UV beam (Δλ_3w ~ 3.5 nm) and a 351-nm beam act as the probe and pump beams, respectively. The frequency of the probe was tuned so that the beat frequency of the crossed beams was resonant with ion-acoustic waves in the plasma, causing Brillouin scattering, which transferred energy between the beams. The results will be compared to LPSE simulations to understand limitations of linear CBET modeling.