RE: Cerium Compounds

["Gary T. Pepper" <gpepper@capitalnet.com>]

At 10:30 AM 4/27/1998 -0500, you wrote:
>Speaking of cerium, I have a very old container of cerium oxide which is
>mildly radioactive.  I have not run a gamma scan on it yet and have
>wondered what radionuclide is emitting the gamma radiation I am
>detecting outside of the metal can.  This material was manufactured by
>the Optical Equipment Company in CA.  Any ideas??
>

Ce-142, an alpha emitter, has a natural abundance of 11.07% (half-life of
1.58E23 s).  I suspect that you are detecting the weak gammas (or x-rays)
from it.

Regards,

Gary Pepper
Radiation physics consultant

Ottawa, Ontario, Canada
e-mail:gpepper@capitalnet.com