Word: neutron
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which was marked to show how many feet and inches of the rod remained within the pile. "Pull it to 13 feet, George," Fermi said calmly, watching the meters set up to measure the neutron emission inside the pile. As Weil withdrew the rod, the meters clicked faster and faster. Fermi did some calculating with the little slide rule he always carried with him. "This is not it," he said. The rate of radiation leveled off as neutron emission from uranium and neutron absorption by cadmium came into equilibrium...
...CLOSE : Now about the neutron bomb, which is supposed to destroy people and leave buildings intact. Well, we approve of this because it goes along with the American ideal of the preservation of the home...
...cotton swab, for example, can be rubbed over a suspect's hand, irradiated, and its gamma rays studied to determine whether the man has fired a gun. Infinitesimal traces of gunpowder components left on the hand by explosion gases show up unmistakably under neutron analysis...
...sensitivity of the technique extends to one-billionth of a gram. It is a marvel at detecting the presence of poison, easily spotting a thimbleful dissolved in ten tank cars of water. Neutron analysis can get along with specimens far smaller than those needed for conventional chemical analysis: a fragment of lint, a strand of hair, a fleck of paint will suffice. Happily, the radioactivity caused by the neutrons soon dies down, and once studied, the evidence can safely be brought into a courtroom...
...Neutron activation analysis has yet to be ruled on officially by a high U.S. court, but its backers are confident; the technique claims extreme accuracy-comparable to the best chemical techniques-and its sensitivity offers crime detection a powerful new weapon. Says Dr. Vincent Guinn, a radiochemist who is director of a joint project of the Atomic Energy Commission, General Dynamics Corp. and the Los Angeles police department: "Neutron activation analysis is no cure-all for crime, nor do I think it will replace regular chemical analysis procedures...