Measurements of Plasma Temperature and Density Profiles Using Grid Image Refractometry for Laser Fusion Research

Electron density ($n_e$) and temperature ($T_e$) profiles of coronal plasma have been experimentally characterized using the grid image refractometer\footnote{R.S. Craxton, et al, Phys. Fluids B 5, 4419 (1993).} recently implemented at the Nike KrF laser facility (Nike-GIR). This instrument measured propagation angles and transmissions of probe laser ($\lambda = 263$ nm, $\Delta t = 10$ psec) beamlets refracted through a CH plasma produced by the Nike laser pulse ($\sim 1$ nsec FWHM) with the intensity of $1.1 \times 10^{15}$ W/cm$^2$.\footnote{J. Oh, et al, BO4.2, APS DPP (2013).} The measured angles were processed by an iterative algorithm to construct self-consistent $n_e$ profiles. The spatial profile of $T_e$ was also examined using the obtained $n_e$ profiles and the measured transmission data. The resulting $n_e$ and $T_e$ profiles were verified to be self-consistent with the measured quantities of the refracted probe light.