A unit of activity equal to one million disintegrations per second. Symbol, Rd. It was proposed by E. U. Condon and L. F. Curtiss of the U.S. Bureau of Standards in 1946 and approved by the National Research Council in 1949, but it never really caught on. In SI units, one rutherford = 1,000,000 becquerels.
The 1955 NRC Glossary¹ used the symbol “rd” and defined two units, one with the definition above, and the other “that amount of substance undergoing” one million disintegrations per second.
1. National Research Council.
A Glossary of Terms in Nuclear Science and Technology.
New York: American Society of Mechanical Engineers, 1955.
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