I am a particle physicist. Using lead smelted in ancient Rome as radiation shielding will improve the signal to noise ratio in my experiment.
There is really no reasonable alternative so I will need to destroy a few ingots. As a scientist I very much understand the frustration of historians over the destruction of artifacts before they can be studied. As a physical scientist I have access to scientific resources not easily available to archeologists and historians. I can devote a small part of my budget and expertise to characterizing the ingots before I process them.
I would like the input of historians as to how I should direct my resources. Please do not consider the monetary cost of the test, I just want to know what data is most important.
Thanks
Ps. Sorry for the semi-repost. ‘itsallfolklore’ provided me some fantastic advice on how to revise the question for this forum.
how much lead are you actually talking about?
a little background about why ancient lead is so valuable to physicists.
The radiation from radioactive particles interferes with our detectors in the form of false positives. Lead ore contains a trace amount of uranium. When a uranium atom decays it goes through a series of transmutations ultimately becoming a stable lead isotope. Wikipeia can provide more detail here: (http://en.wikipedia.org/wiki/Actinium_series#Actinium_series). One of the steps in this chain is an unstable, radioactive, form of lead. The half life for this form of lead is about 20 years. This means that lead ore, by virtue of its uranium content, will be constantly generating fresh radioactive lead as fast as it decays.
The smelting process separates lead from uranium very effectively. Unfortunately it is thousands of times more difficult to separate one isotope of lead from another isotope of lead. This is the same reason so much of the Manhattan project had to be devoted to uranium enrichment. But, once the uranium is removed, fresh radioactive lead stops being created. The radioactive lead content of a given sample of lead will begin to decrease over time.
Lead looses about half its radioactivity every two decades. After about a hundred half lives the radiation output is negligible. Hence it is much better for shielding radiation detectors. Radioactive radiation shielding on a detector is kind of like having a glow in the dark camera lens.