Page 340 - Demo

Nuclear Weapons of the Atomic AgeBeginning in 1949, the American Museum of Atomic Energy in Oak Ridge, Tennessee started exposing dimes to nuclear radiation and giving them out as souvenirs. Over a million dimes were made radioactive before the program ended.The irradiated dimes were created to demonstrate a principle of atomic energy through a dramatic demonstration of neutron activation. After a visitor took a dime from their pocket, it went into a special leadlined chamber where it was irradiated. As it dropped out through a slot, a Geiger counter clicked to show that the dime was radioactive. The coin was then sealed into a holder and returned to the museum visitor as a souvenir. If you didn%u2019t happen to have a dime, the museum supplied one for you.The round, 25-mm holder had a rolled aluminum rim with a plastic cover over the dime. Because visitors generally supplied their own coins, a wide variety of dates were processed, with Roosevelt dimes being the most common, although many Mercury dimes were irradiated as well. With the backs of the coins not visible through the holders, later collectors couldn%u2019t know a dime%u2019s mint mark without removing it. So, they began collecting irradiated dimes only by year. While a coin could easily be removed from its container, that would destroy its souvenir value%u2014but that didn%u2019t stop kids from removing the dimes for spending money.According to a press release from 1954, %u201cA mixture of radioactive antimony and beryllium is enclosed in a lead container. Gamma rays from the antimony are absorbed by the beryllium atoms and a neutron is expelled by the beryllium atom in the process. These neutrons, having no electrical charge, penetrate silver atoms in the dime. Instead of remaining normal silver-109, they become radioactive silver-110.%u201d The press release then added, %u201cRadioactive silver, with a half-life of 22 seconds, decays rapidly to cadmium110.\centage of coin%u2019s silver was irradiated, and by the time the visitor left the Museum, their dime had almost no radioactivity left. Sometimes the museum sent an irradiator machine out on the road to nearby fairs, such as one in Memphis. Another was set up as far away as the 1964 World's Fair in New York, where irradiated dimes were put into blue plastic holders which featured an atomic logo. The year after the fair, the U.S. Mint began making dimes out of nickel-clad copper%u2014with no silver. Because the irradiator only worked with silver, museum employees bought up rolls of older dimes to keep the popular program going. It was finally shut down in 1967.The Irradiated Dimes of Oak Ridge, TennesseeMiss Universe, Aspasra Hongsakula of Bangkok, Thailand, receives a radioactive dime as a souvenir of her visit to the American Museum of Atomic Energy in 1966.1941 irradiated Mercury dime 1962 irradiated Roosevelt dime