the transmutation reactions which led to the production of these radioisotopes were effected first with the 27-inch cyclotron, which later became the 37-inch cyclotron, in the old Radiation Laboratory, and finally with the 60-inch cyclotron in the Crocker Laboratory." Our association extended over a period of about five years (1936-1941) even though he left Berkeley to accept a position at Harvard University near the end of 1938. "My collaborator in most of this work was a young nuclear physicist, John J. of the 8,000,000 administrations per year of radioisotopes in the United States, some 90% utilize either iodine-131, cobalt-60 or technetium-99m." "I became involved in the discovery of a number of radioisotopes that in subsequent years have found substantial applicants in the diagnosis and treatment of disease. To give a better idea of what was involved in these investigations, I will quote parts of a presentation made by Seaborg at the 1970 annual meeting of the Society of Nuclear Medicine: Radioactive elements fell in our laps as though we were shaking apples off a tree." Livingood would later say, "It was a wonderful time. I like to imagine, and it is possible, that some of these cards are associated with the discovery of Co-60. Using this method, Seaborg and Livingood discovered and characterized a number of radioisotopes including I-131, Fe-55, Fe-59, Zn-65 and Co-60. While I am not sure what the roman numeral at the end indicates, I suspect that it refers to a particular experimental run. These three preparations would be indicated as Fe of Fe + D, Co of Fe + D, and Mn of Fe + D respectively. Seaborg then dissolved the target and chemically separated out three elements: iron (Fe), cobalt (Co), and manganese (Mn). In one important experiment, Livingood bombarded an iron target with deuterons. Let me use an example to explain what the information on the cards indicates. The writing on the cardboard holders (photo to right) is as follows:Įach sample holder is 1 1/4" wide (not counting the small tab) and 2 1/2" long. Livingood then analyzed the properties of the induced radioactivity with an electroscope. He then placed these preparations on cardboard and covered them with cellophane. Livingood activated samples in a cyclotron and Seaborg separated out the elements of interest. This would have been in 1936 to 1938-one of the small boxes in which these came has "Oct 9 '37" indicated in Livingood's handwriting. These items were donated by Glenn Seaborg and identified by him as activated samples that he and John (Jack) Livingood had produced at the University of California in Berkeley.
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