Possible Evidence for Non-Thermal Electron Energy Distributions in Z-Pinch Plasmas

Summary form only given. Radially resolved X-ray spectra were recorded with a time resolved Johann spectrometer on Double EAGLE. Four percent Cl was added as an optically thin trace element to the Ar in individual shells of multi shell gas-puff loads to study the implosion and radiation characteristics of these shells. The ratios of observed Cl line intensities were compared with predicted values using CRE codes to determine radial distribution of electron temperature, T_e and ion density, N_i. Preliminary analyses give a higher value for T_e (1280 eV) and lower value for N_i (7times10¹⁹ cm^-3) when using the ratio of the resonance lines (Ly_alpha/He_alpha+IC) together with the IC/He_alpha line ratio than is obtained with the ratio of the jkl satellites to the IC line intensity together with the IC/He_alpha ratio (T_e<600 eV, 10²⁰<Ni<10²¹ cm^-3). The apparent two temperature plasma composition implied by the analysis will be discussed to determine if it represents two axially separated radiating regions or if it is a possible indicator of a non-thermal electron population.