Non-destructive method for measuring the D2/DT fill pressure and permeability for direct drive plastic shells

A technique has been developed which makes it possible to measure in a non-destructive way the fill pressure of a transparent direct drive fusion shell. The accuracy of these measurements is within 2% of the best known values for the system D2/DT. By raising the temperature of the shells and allowing them to leak for a certain time between the pressure measurements, their leak rate and permeability can be determined accurately. The technique is simple enough to be used as a tool for quality control to eliminate shells with a leak rate faster than that set by established standards; the surviving shells will than be automatically characterized regarding their fill pressure and their leak rate. (author). 3 refs, 6 figs, 2 tabs