Around the Lab
Two-Plasmon–Decay Suppression Using Laser Wavelength Detuning
Three-dimensional LPSE simulations of an OMEGA implosion have been run, varying amounts of frequency detuning to determine the fraction of the incident laser energy converted into hot electrons. The simulations used two types of detuning, including (1) “multicolor,” where each beam was split into three frequencies, and (2) “tiled,” where each beam is monochromatic, but the different beams have three different frequencies (alternating between beams). The simulations show that, in either case, as little as 0.5% frequency detuning is sufficient to suppress hot electrons in current OMEGA implosions.
The laser–plasma simulation environment (LPSE) computer code designed to solve problems in high-energy-density physics (HEDP) has successfully reproduced experiments including the measured plasma-wave amplitudes and hot-electron generation. The addition of a laser bandwidth model to LPSE has enabled the exploration of new strategies for mitigating laser–plasma instabilities. Coupling LPSE with the recent upgrade to the OMEGA EP Laser System to support ultraviolet detuning up to 0.7% makes it possible to investigate these results in upcoming experiments.