Fusion Science and Technology / Volume 51 / Number 4 / May 2007 / Pages 606-610
Progress has been made in reducing and quantifying residual gases in shells manufactured by the silicon doped glow discharge polymer (SiGDP) to glass process. Previously, glass shells were made using a high temperature, open-air box oven. If the temperature profile used was sufficient, clear, colorless shells were obtained which had ~1/3 of an atmosphere of residual gas consisting of a mixture of N2, O2, CO and CO2 with generally N2 and CO2 being the major constituents. Improvements to the process were made by utilizing a controlled atmosphere, high temperature oven and developing an improved temperature profile for the SiGDP to glass conversion process. It is now possible to manufacture clear, colorless glass shells containing noble gas(es), which is a first for the ICF program. In addition, the improvements in our process has led to shells containing less residual gas (N2, CO, and CO2) than previously obtainable. Tailored deuterium halflifes are also possible by adjusting the final sintering temperature which results in glass that is very near but not full density which allows in some cases for fielding of glass shells with half-lives which can be more suitable to the experimentalist.