Easy polonium-beryllium neutron source: assembly, disassembly, and discussion

A 5-millicurie sealed Po-210 source leased commercially for antistatic applications is brought into contact with a piece of bulk beryllium metal in the proximity of a He-3 neutron detector, with the resulting neutrons being detected. This assembly is taken apart and reassembled several times in the course of the video, as we watch the neutron counter respond. My objective is to illustrate the prolific Be(a,n) reaction in a concrete embodiment, which I suggest is a (relatively) safe, easy, and inexpensive route to neutrons for contemporary amateur and school physics projects. The “Nuclespot“ polonium source is available for lease without a specific license in the United States; contact Amstat Industries. It costs about $175 / year. Bulk beryllium metal is routinely available on eBay in convenient sizes for this type of construction; my piece ran about $50. (NEVER attempt to cut or machine beryllium!) Finally, some evidence is shown about the efficacy of adding more mo