Tomographic Optical Imaging of a Pulsed Atmospheric Pressure Plasma Jet

Advances in laser diagnostics and models have been leveraged to investigate plasmas in two spatial dimensions (2D), but the spatially complex structure in actual plasmas requires techniques that can provide a more complete three-dimensional (3D) picture. To address this limitation, a plasma tomographic optical imaging diagnostic has been developed at Sandia National Labs. The system includes four intensified cameras that can measure eight angular projections of the light source with a temporal resolution of 5 ns. An algebraic reconstruction technique (ART) is used to determine the light intensity at each voxel within the interrogated volume using the method of projections onto convex sets. Initial efforts have focused on 3D optical emission imaging. Development challenges have included reconstruction algorithm development and achieving sufficient 3D spatial and temporal resolution to resolve features of interest.