Fusion Science and Technology / Volume 47 / Number 4 / May 2005 / Pages 1139-1142
Technical Paper / Fusion Energy - Inertial Fusion Technology
We are performing research and development to increase production quantity and yield for Inertial Fusion Energy targets for laser fusion. A key component of the laser fusion target is an approximately 4 mm diameter foam shell. To facilitate large-scale production, research into optimization of foam shell gelation and hardening times to reduce non-concentricity of the foam shell is underway. Additionally, we are examining methods to modify the current laboratory bench scale process for initial foam shell formation, various fluid exchanges, and sealcoat chemistry into a continuous process in collaboration with Schafer Corporation. The proposed process utilizes porous tubing sections to perform fluid exchanges in a long (200 m-1 km) continuous path of tubing extending from the triple orifice generator currently used to encapsulate and form the foam shell.
Real-time process control has been applied to the triple orifice generator to control the diameter of the foam shell. The system makes use of a pair of photodiode sensors in a closed loop feedback control system incorporating a variable speed process pump. Empirical results indicate the process control loop is capable of identifying wet shell diameters to an approximate standard deviation of 80 to 90 m, on par with characterization results indicating true shell diameter standard deviations of 30-80 m.