A full-scale ITER toroidal interferometer and polarimeter (TIP) prototype has been constructed and tested both in the laboratory and on the DIII-D tokamak. The TIP prototype measures electron density using two approaches. Two-color interferometry is carried out at 10.59μm and 5.22μm using a CO2 and Quantum Cascade Laser (QCL) respectively while a separate polarimetry measurement of the plasma...
A novel optical spectrometer was built that enables measurements of Thomson scattering from electron plasma waves with 2-ps time resolution. Pulse-front tilt introduced from a diffraction grating scales with aperture diameter and can limit the achievable time resolution of a streaked spectrometer. The spectrometer presented in this work uses an echelon optic to break the aperture into series...
A novel combined diagnostic capable of measuring multiscale density fluctuations that extend from MHD to the lower-ETG range has been designed, installed, and operated at DIII-D. The combined diagnostic was constructed by adding a heterodyne interferometer to the pre-existing phase contrast imaging (PCI) system, both of which measure line-integrated electron-density fluctuations. The...
A digital holography (DH) surface erosion/deposition diagnostic is being developed for 3D imaging of plasma facing component (PFC) surfaces in situ and in real time. Digital holography is a technique that utilizes lasers reflected from a material surface to form an interferogram, which carries information about the topology of the surface when reconstructed. As described in this paper, dual...
