Optimization of the hard X-ray yield from a heterogeneous Z-pinch

Summary form only given. Conventional Z-pinches are known to be an effective source of soft X-rays. However, this approach has limited control in redistributing the radiation spectrum, specifically toward the hard X-Ray regime where photon energies are >10 keV. The generation of such energetic photons requires both high densities and temperatures in the plasma. Due to the Rayleigh-Taylor instability and current (mass) limitations, these plasma conditions are difficult to achieve simultaneously. To produce a harder emitted X-ray spectrum, the "Liner-Converter" scheme was proposed at the Kurchatov Institute. This technique uses the thermal flux from the end of a low-Z pinch to rapidly heat a thin, high-Z converter linked to the edge of the pinch. A temperature of 10 keV can be achieved in the converter by fast and efficient heat transfer from the low Z-pinch liner; this results from the strong dependence of thermal flux on electron temperature. Using a low-Z pinch liner minimizes radiation losses and instability growth, while maximizing end-losses to the converter. By employing a separate converter, there is flexibility in choice of materials and radiator geometry. Computer simulations of this concept and experiments on the 3 MA, S-300 generator will be presented.