Martin Kamen

Martin David Kamen (August 27, 1913, Toronto – August 31, 2002, Montecito, California) was an American chemist who, together with Sam Ruben, co-discovered the synthesis of the isotope carbon-14 on February 27, 1940, at the University of California Radiation Laboratory, Berkeley.
Biography.
Kamen was born on August 27, 1913, in Toronto, the son of Russian Jewish immigrants. He grew up in Chicago. He received a bachelor's degree in chemistry from the University of Chicago in 1933 and obtained a PhD in physical chemistry from the same university in 1936. Thereafter he sought a research position in chemistry and nuclear physics under Ernest Lawrence at the radiation laboratory in Berkeley, where he worked without pay for six months until being hired to oversee the preparation and distribution of the cyclotron's products. Although carbon-14 was previously known, the discovery of the synthesis of carbon-14 occurred at Berkeley when Kamen and Ruben bombarded graphite in the cyclotron in hopes of producing a radioactive isotope of carbon that could be used as a tracer in investigating chemical reactions in photosynthesis. Their experiment resulted in production of carbon-14.
In 1943, Kamen was assigned to Manhattan Project work at Oak Ridge, Tennessee, where he worked briefly before returning to Berkeley. He was fired from Berkeley in 1945 after being accused of leaking nuclear weapons secrets to Russia, and for a time was unable to obtain an academic position, until being hired by Arthur Holly Compton to run the cyclotron program in the medical school of Washington University at St. Louis. Kamen taught the faculty how to use radioactive tracer materials in research, and his own interests gradually shifted into biochemistry.
In 1957, he moved to Brandeis University in Massachusetts, and in 1961 he joined the University of California, San Diego, where he remained until his retirement in 1978.
Martin Kamen died August 31, 2002, at the age of 89 in Montecito (Santa Barbara), California. He was a longtime resident of Casa Dorinda retirement home, where he was well-liked and admired for helping others.
Scientific contributions.
By bombarding matter with particles in the cyclotron, radioactive isotopes such as carbon-14, were generated. Using carbon-14, the order of events in biochemical reactions could be elucidated, showing the precursors of a particular biochemical product, revealing the network of reactions that constitute life. Kamen is credited with confirming that all of the oxygen released in photosynthesis comes from water, not carbon dioxide. He also studied the role of molybdenum in biological nitrogen fixation, the biochemistry of cytochromes and their role in photosynthesis and metabolism, the role of iron in the activity of porphyrin compounds in plants and animals, and calcium exchange in cancerous tumors.
Controversies.
Accusations of Communist spy activity.
Kamen came under long-term suspicion of espionage activity beginning in 1944. He described his experiences during this era in his autobiography, "Radiant Science, Dark Politics". He first aroused suspicion while working at Oak Ridge. A cyclotron operator prepared radioactive sodium for an experiment, and Kamen was surprised that the resulting sodium had a purple glow, indicating it was much more intensely radioactive than could be produced in a cyclotron. Kamen recognized immediately that the sodium must have been irradiated in a nuclear reactor elsewhere in the facility. Because of wartime secrecy, he had not been aware of the reactor's existence. He excitedly told his colleagues about his discovery. Shortly thereafter, an investigation was launched to find out who had leaked the information to Kamen.
After returning to Berkeley, Kamen met two Russian officials at a party given by his friend, the violinist Isaac Stern, whom he sometimes accompanied as a viola player in social evenings of chamber music. The Russians were Grigory Kheifets and Grigory Kasparov, posted as undercover KGB officers in the Soviet Union's San Francisco consulate. One of them asked Kamen for assistance in getting experimental radiation treatment for a colleague with leukemia. Kamen made inquiries, and in appreciation the official invited him for dinner at a local restaurant. In the aftermath of the Oak Ridge incident, Kamen was under continuing surveillance by FBI agents who observed the July 1, 1944 dinner, where Kamen was alleged to have discussed atomic research with Kheifets. Kamen lost his Berkeley position shortly afterwards.
The House Committee on Un-American Activities summoned Kamen to testify in 1948. Subsequently the State Department refused to issue him a passport. In 1951 the Chicago Tribune named him as a suspected spy. Kamen attempted suicide. After a 10-year effort to establish his innocence and prove that he had been blacklisted as a security risk, he won a libel suit against the Tribune in 1955 and was able once again to obtain a passport.
Recognitions.
Kamen became Guggenheim Fellowship recipient in 1956 and two years later he became a fellow of the American Academy of Arts and Sciences in 1958. In 1962, Kamen was elected as a member of the National Academy of Sciences. On April 24, 1996, he became a winner of the Enrico Fermi Award. He was awarded the 1989 Albert Einstein World Award of Science. 
Books.
Kamen, Martin D. "Radiant Science, Dark Politics: A Memoir of the Nuclear Age", Foreword by Edwin M. McMillan, Berkeley: University of California Press, 1985. .