How about using gadolinium: http://unitednuclear.com/index.php?main_page=product_info&cPath=16_17_69&products_id=141
I bought a beryllium marble from them a few years ago for a coupe of bucks, but they aren't listing it anymore. Hoyt Stearns On Sat, Dec 8, 2012 at 4:04 PM, Axil Axil <[email protected]> wrote: > *"If I want a small piece of beryllium that will fit in the well of an > Am-241 source, to get maximum neutron flux, I might arrange to buy some > pieces like that."* > This is wrong thinking. To get the most neutron intensity, a very thick > piece of beryllium (Be) is required to increase the probability of alpha > particle interaction with a Be atom. > > A very thin piece of Be will not convert all the alphas to neutrons. After > the neutron is produced, it will not be absorbed by Be atoms so a thick > berillium tagret will not affect the neutron. > Cheers: axil > > > On Sat, Dec 8, 2012 at 5:28 PM, Abd ul-Rahman Lomax > <[email protected]>wrote: > >> At 01:51 AM 12/8/2012, Eric Walker wrote: >> >>> On Fri, Dec 7, 2012 at 10:47 PM, Abd ul-Rahman Lomax <<mailto: >>> [email protected]>a**[email protected] <[email protected]>> wrote: >>> >>> Would it cut cleanly, if thin enough, or would it crush? There could be >>> a way to pull this off safely, with capture and proper disposal of any >>> dust. Do it under water? Waste disposal? So ... maybe. But that's not for >>> now. >>> >>> >>> The problem is that you don't find out if it what you did was safe for >>> five years, and then you have a 1/3 chance of dying or being disabled. >>> >> >> The danger of beryllium is real and subtle. However, it's also being >> exaggerated here. If one is exposed to serious levels of airborn beryllium, >> which are pretty small, yes, even a subacute exposure have no symptoms for >> many years (sometimes 20) and can pop up years later as very serious >> chronic disease. But the experience with beryllium was with workers at >> beryllium plants who were exposed to the material, at substantial levels, >> day after day, for years, and if those people contracted berylliosis, >> *then* there was a one-third chance of a seriously harmful outcome, like up >> to and including death. >> >> If I were to take a piece of thin beryllium foil and cut it with some >> snips, once or a few times, the chance of serious beryllium exposure is >> extremely small. And even that "bold move" I'm not going to engage in >> without a lot more research, and possible some serious precautions. I'm >> going to experiment first with my solid piece of beryllium, which is very >> safe. As long as I don't heat it seriously, or do any of a number of other >> unwise things. >> >> I have children. I have utterly no willingness to risk their health. If I >> were to do anything more bold than allowing this piece of beryllium to sit >> on top of an Am-241 smoke detector source, I would not do it here. And I >> might easily not do it at all. If I want a small piece of beryllium that >> will fit in the well of an Am-241 source, to get maximum neutron flux, I >> might arrange to buy some pieces like that. There are places selling >> machined beryllium. And I'd attempt to recover my cost by selling the >> pieces for exactly that application. >> >> The children will not be allowed to handle the beryllium. They will know >> about it, though, and they will know that it is dangerous. Even though it >> appears that one can swallow pieces of beryllium metal without harm, we >> will not run that experiment. >> >> Here is what I will say to anyone considering using beryllium. It's a >> totally cool substance, in many ways. However, anyone who is going to >> handle it should study the MSDS guidance, and take it very seriously. Many >> people have died from contact with beryllium. Airborn, it is totally nasty. >> >> There can be a bit of hysteria around it, see http://www.f1fanatic.co.uk/ >> **2007/02/08/banned-beryllium/<http://www.f1fanatic.co.uk/2007/02/08/banned-beryllium/> >> >> It's a judgment call. Beryllium has been used for jet aircraft brakes. >> That generates dust. I can see why people would get upset. Bad News for Air >> Force Mechanics. Beryllium for an engine piston, as described in the >> f1fanatic site probably does not emit serious beryllium in engine exhaust, >> or else the piston would wear out quickly. But that could be addressed by >> testing. >> >> I'm looking forward to handling the metal, it is reputed to be amazingly >> light, very palpably so. Source after source said that beryllium metal >> parts were not a problem, even while warning very seriously about dust >> (metal, oxide, or salts of beryllium). Absorption through the skin does not >> appear to be a problem, doesn't seem to happen. They say that if a piece of >> beryllium is lodged beneath the skin, remove it... that does seem like a >> good idea, eh? >> > >
