Two-color high intensity laser plasma interaction phenomena, and status of experiments on the UT³ laser system
We report the status of two-color high intensity laser-plasma interaction experiments on the UT³ laser system at the University of Texas at Austin. After an outline of the experimental apparatus, an overview of the motivating theoretical work, and a characterization of the performance of our Chirped Pulse Raman Amplification system (CPRA) we report the status of our most recent experiment. We have attempted to seed the growth of the Raman Forward Scattering (RFS) instability in order to produce electrons at lower driving pulse power than is conventionally needed. We have been unsuccessful, and provide reasons why and recommendations for future modifications to the experimental apparatus. The most significant conclusion is that the CPRA system as it is now is not appropriate for this experiment because the observed RFS spectrum is at higher wavelength than our system. Possible future changes include either amplifying a separate barium nitrate sideband at 938 nm through the CPRA system or using a different Raman active medium after the main 800 nm UT³ pulse is compressed. The feasibility study of these possible modifications is not yet complete.