Samuel Theodore Cohen (January 25, 1921 – November 28, 2010) was an American physicist who is generally credited as the father of the neutron bomb. Biography Cohen's parents were Austrian Jews who emigrated from London, England. He was born on January 25, 1921, in Brooklyn and raised in New York City. He studied mathematics and physics at University of California, Los Angeles before joining the United States Army after the Japanese attack on Pearl Harbor. In 1944 he worked on the Manhattan Project in the efficiency group at Los Alamos and calculated how neutrons behaved in Fat Man, the atomic bomb that was later detonated over Nagasaki, Japan. After the war he studied for his Ph.D. at Berkeley before dropping out to join the RAND Corporation. At RAND Corporation in 1950, his work on the intensity of fallout radiation first became public when his calculations were included as a special appendix in Samuel Glasstone's book The Effects of Atomic Weapons. Cohen was personally responsible for recruiting the famous strategist Herman Kahn into the RAND Corporation. During the Vietnam War, Cohen argued that using small neutron bombs would end the war quickly and save many American lives, but politicians were not amenable to his ideas and other scientists ignored the neutron bomb in reviewing the role of nuclear weapons. He was a member of the Los Alamos Tactical Nuclear Weapons Panel in the early 1970s. President Carter delayed development of the neutron bomb in 1978, but during Ronald Reagan's presidency, Cohen claims to have convinced Reagan to make 700 neutron bombs, 350 shells to go into the 8 inch (200-millimeter) howitzer and 350 W70 Mod. 3 warheads for the Lance missile. "Clean" nuclear tests In 1956, President Dwight D. Eisenhower announced the testing of a 95% "clean" (2-stage) fusion weapon, later identified to have been the July 11 Navajo test at Bikini Atoll during Operation Redwing. This weapon had a yield of 4.5 megatons. Previous "dirty" weapons had fission proportions of 50–77%, due to the use of uranium-238 as a "pusher" around the lithium deuteride (secondary) stage. This is deliberate; the fusion reactions give off large quantities of 14.1 MeV neutrons, which have more energy than the 1.1 MeV "fission threshold" for U-238. This means the neutrons, which would otherwise escape, create fission reactions in the neutron reflecting 'tamper', increasing the overall yield of the weapon essentially "for free". The 1956