Flow induced beam deflection measurements in ablation plasmas

We will make measurements of ponderomotive laser deflection in a well characterized ablation plasma.  Laser driven acoustic waves in flowing plasma are enhanced when the transverse flow reaches the sound speed, driving density perturbations that cause beam deflection in the downstream direction[1,2].   Our experiments will use a low-density plasma with a flow velocity similar to its sound speed, making ponderomotive beam deflection angles much larger than the small refraction angles expected in these conditions.    

The measured plasma conditions along the beam path will be used to compare beam deflections to ponderomotive beam deflection models.