of negotiations that eventually led to the Partial Test Ban Treaty, which banned most forms of nuclear testing. He was committed to preventing nuclear weapons proliferation. He spoke at Pugwash Conferences, and wrote a paper dispelling the myth that reactor-grade plutonium could not be used for nuclear weapons. Mark was member of the American Mathematical Society and the American Physical Society, and served on the United States Air Force's Scientific Advisory Board, and its Foreign Weapons Evaluation Group. After he retired from Los Alamos in 1973 he served on the Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards, and was a consultant for the Nuclear Control Institute. One of his last papers was on Iraq's nuclear weapons capability. Mark died in Los Alamos, New Mexico, on March 2, 1997, from complications related to a fall. He was survived by his wife Kathleen, daughters, Joan, Elizabeth Mark and Mary, and sons, Thomas, Graham and Christopher, his brother, James and sister Dorothy . Notes References External links Audio Interview with J. Carson Mark by Richard Rhodes Voices of the Manhattan Project 1913 births 1997 deaths Canadian emigrants to the United States Manhattan Project people People from Kawartha Lakes University of Manitoba faculty University of Toronto alumni University of Western Ontario alumni 20th-century Canadian mathematicians Los Alamos National Laboratory personnel Fellows of the American Physical Society Accidental deaths from falls