Distribution of Ne gas permeabilities in glass laser targets

A 3.6 million sample of sized, soda-lime glass microbubbles was filled to various total percent fills with Ne. The batches were outgassed isothermally at 498K. The partially filled batches outgassed faster because initially only the more permeable microbubbles were filled. Two models were used to study permeation, with values of tau (the time constant) ranging from 1-100. The data agree better with the model skewed to the fast time constant side. An analysis of the dimensions indicates that the permeability must be responsible for most of the distribution. The reason for this is not known; however, it may be due to variability of chemical composition or to varying degrees of phase separation.