Fusion Science and Technology / Volume 51 / Number 4 / May 2007 / Pages 559-563
In this paper we show that the ambient temperature measured leakage time constant, RT, is related to the leakage at cryogenic temperature, RC, by
RC = 0.23DTVsh/RT
where DT is the density of cryogenic DT vapor, and Vsh is the internal volume of the shell. We then calculate the size of voids that may result from leakage at the Be/DT interface, depending upon the number of leakage sites and RT. Even for the slowest leakers the potential void growth is excessive. Reasons that voids have not been seen in DT layering experiments to date include the lack of a technique to see isolated micronish bubbles, however possible mechanisms preventing void formation are also discussed.