Fusion Science and Technology / Volume 52 / Number 4 / November 2007 / Pages 963-968
Technical Paper / Inertial Fusion Technology: Drivers and Advanced Designs
The Z-pinch driven fusion reactor will require extremely high current pulses to generate sufficient x-ray flux for the fusion target implosion. The fusion target is coupled to the pulsed power system through a recyclable transmission line (RTL) that is presently envisioned made of carbon steel. The energy released by the fusion pulse is absorbed by liquid flibe (Li2BeF4) coolant and by the RTL material which is partially vaporized and ionized. The objective of this paper is to characterize the recombination of vaporized metal halides in the presence of ferritic steel in a plasma with parameters similar to those expected in the Z-IFE chamber (plasma density < 2 × 1018 cm-3, Te < 40000 K). Using a substitute eutectic salt (Na2MgCl4) instead of flibe, we find experimentally that the three-body recombination rate of iron with chlorine is larger than that of sodium with chlorine. The measured recombination rates are compared to equilibrium recombination rates calculated at lower temperature (5000 K). The results suggest that an effective scheme for the removal of ferritic fluorite from the liquid flibe coolant may be needed in a Z-IFE reactor in addition to the mechanical separation of carbon steel RTL material required for recycling.