A unit of activity, symbol Ci, equal to 3.7 times 10 to the 10th becquerels, originally based on the activity of one gram of radium-226. It is the working unit in US practice and on many source labels, where radiography sources are rated in tens of curies and contamination in microcuries or picocuries. Converting carefully between curies and becquerels is a routine part of shipping papers and licence limits.
New iridium source came in at 98 curies, so the radiographers need the full exclusion zone tonight.
Also heard as
- Ci
Related terms
Becquerel
The SI unit of radioactivity, equal to one atomic decay per second.
Sealed source
Radioactive material permanently sealed in a capsule so it cannot escape under normal use.
Shot
A single industrial radiography exposure, used to x-ray a weld with a gamma source or X-ray tube.
Half-life
The time it takes for half the atoms of a radioactive isotope to decay, a fixed value for each nuclide.