Thanks Henry. That should give me plenty of reading material for a Sunday afternoon.
I am working on another contract. This time for robotic laser welding on aluminum can enclosures for lithium ion batteries used on wind and solar energy farms. It is partly funded with DOE money.
We have to meet a hermetic seal requirement of 10^-7 helium. We can meet it sometimes, but other times we only meet 10^-5 helium. So far I have not seen any cracks but I am on a witch hunt anyway since they are still blaming the welds.
OB