Pascal Brock writes:

Harold Levi writes:

Bruce Perdue writes:

The following is taken from the TAMS Journal, Vol.14, No. 1, February 1974.

The article is accompanied by an example of a 1960 Roosevelt dime in the plastic holder (front & back view).

As a high school freshman in NYC at the time of the World's Fair, I visited it many times. During one of my visits, I had a dime irradiated at this exhibit. One problem was that the dime could easily be popped out of the holder & spent (as my younger brother eventually did with his). Likewise, another dime could then be reinserted. So, there is no way to guarantee that the dime in a holder today is the irradiated dime. I read somewhere that the radiation dosage was so low and the half-life so short the dime would no longer be radioactive.

Here are scans of my irradiated dime from the NY World's Fair. It is a 1948 Roosevelt dime. I have never removed the dime, so it is the one that I had originally had irradiated.

Here is a scan of my 1951 Roosevelt neutron irradiated dime by the American Museum of Atomic Energy. The reverse is blank. I purchased it from a coin dealer in February 1998 for $5.00.

Besides the previously mentioned TAMS article, there was an excellent article (which is too long to copy) in Coin World on the irradiated dimes. It's entitled, "Dimes tell Oak Ridge story" by Michael E. Marotta. COIN WORLD, Monday, October 4, 1999, pp. 20 & 28. The article discusses the dimes irradiated at both the museum & the NY World's Fair and is accompanied by pictures of a number of irradiated dimes.

There was also another article on irradiated dimes, entitled "Fallout In Your Pocket." in Rochette, Edward C. 1985. The Other Side of the Coin. Frederick, CO: Renaissance House. pp. 72-73.Accompanying the article is a picture of an encapsulated "1962 "Cadmium'" dime. There is one part of the article which discusses the irradiation process at the museum.

". . . He [T.F.X. McCarthy, then information officer, Oak Ridge Institute of Nuclear Studies] assured me that only a few atoms of the dime's silver had been made radioactive during its exposure in the radiation device and that silver loses its radioactivity at such a fast rate that the dime would 'probably' fail to register on a Geiger counter by the time the visitor leaves the museum.

Making dimes radioactive was discontinued only when silver coins disappeared from circulation in the mid-1960s. When exposed, the silver in the dimes changed from Ag-109, which absorbed neutrons very easily, to AG-110, which is radioactive. The dimes, for about four minutes, were capable of emitting low-energy beta radiation. After 10 half-life periods, less than a tenth of one percent of the original activity remained and could be detected only by highly sophisticated equipment. . . . the exposed silver transformed itself into stable Cadmium-110."

Based upon the foregoing, I find it hard to believe that "If you have a Geiger counter you can confirm this! Indeed, this was done at an early Fest" as was stated in an earlier Esylum." For this to occur, that dime had to be hit with a LOT more radiation than was being used.I would guess the Geiger counter used at the Fest was picking normal background radiation and not radiation from the dime. Indeed, if you turn a Geiger counter on (as I have done in my geology classes), every now and then it will click. That is from normal background radiation.

To read the earlier E-Sylum article, see:IRRADIATED DIMES(www.coinbooks.org/esylum_v14n51a07.html)