Measurement of the electron-ion thermal equilibration rate in a strongly coupled plasma

Summary form only given. We are conducting a laboratory experiment aimed at measuring the temperature equilibration rate between ions and electrons in a strongly-coupled plasma. Theory indicates that this rate could be significantly lower than that given by the usual weakly coupled model (Landau/Spitzer) due to coupled collective modes present in the dense plasma. The plasma under study is formed by heating a hypersonic SF₆ gas jet with a short pulse (~10 ps) laser, resulting in warm electrons (~100 eV) and cold ions (~5 eV). The electron and ion temperatures of the resulting plasma will be independently measured during and after heating, using collective Thomson scattering for electrons and a high-resolution X-ray spectrometer for the ions (measuring Doppler-broadened absorption lines). Determining how the equilibration rate varies from Landau/Spitzer requires very fast diagnostics, since Landau/Spitzer equilibration would occur within ~100 ps. We will present our most recent experimental results