Leo Yaffe

Nuclear Engineering

Pioneer radiochemist: world authority on counting beta-radiation; mastermind behind Canada's foremost research lab for nuclear chemistry at McGill.

"The transmission of knowledge from one generation to the next remains for me the most noble of the professions."

Yaffe was one of the brilliant international team of scientists who made history in wartime Canada with the Atomic Energy project first in Montréal and later in Chalk River - the project that eventually grew into Atomic Energy of Canada Ltd. (AECL). Following the war, Yaffe remained with AECL as director of research in nuclear chemistry. He developed several practical applications of nuclear radiation, including intense sources of cobalt-60 for the treatment of cancer, and radioactive tracers for medical diagnosis and research.

In 1952, Yaffe moved to Montréal where the J.S. Foster cyclotron had just been installed at McGill University. He set up Canada's foremost university research lab for radiochemistry and beganthe work which brought him worldwide acclaim. During his time at McGill, he supervised 39 graduate students and almost as many post-docs in fundamental work on beta measurement techniques, production of uranium-233 from thorium, and proton-induced fission. By 1954, he was associate professor and in 1958 he was appointed Macdonald Professor of Chemistry.

In 1963, with the Cold War raging, Yaffe obtained leave from McGill to move to Vienna as director of research at the International Atomic Energy Agency. Disenchanted with international politics, he returned to Montreal in 1965 and served as head of the Department of Chemistry until 1972. This period is regarded as the "golden age" of chemistry at McGill, years during which the staff of the department doubled and the department granted almost a quarter of the PhDs awarded since the initiation of the doctorate degree in 1910.

In 1974 Yaffe was appointed vice-principal (administration) of McGill, a post he held until he retired in 1981. He also served as president (1981-82) of the Chemical Institute of Canada.

Yaffe's later scientific interests included the use of nuclear methods to determine the age and place of origin of archaeological artifacts. Working with a visiting professor from Turkey and McGill professors of classics and archaeology, Yaffe and his graduate students were able to establish theories about early trade routes in Turkey, Greece, the Caribbean, and those of the Iroquois in the Ottawa Valley.

Yaffe's career encompassed the entire breadth of the Canadian atomic energy program from its wartime origins to the present day.

Sources: McGill Reporter, May 29, 1997; Canadian Chemical News, Jan 1999, Canada's Nuclear Pioneers; Photo: McGill Reporter, May 29, 1997.

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