Investigators said a knowledge of electronics was required to construct the bomb.
Somehow, the IRA had managed to remove the explosives from the hayshed without the army monitors hearing anything, and had used them to construct the bomb that killed the three police officers at Kinnego.
In a signed statement, Mr. Nichols acknowledged helping Timothy J. McVeigh construct the bomb that killed 168 people and destroyed the Alfred P. Murrah Federal Building, but said he had no prior knowledge of the target or of any other co-conspirators.
"You could almost see through your eyelids, it was so bright," Dr. Schreiber recalled to an interviewer in 1980 during a 35th anniversary reunion at Los Alamos of 600 people who had helped construct the bomb.
During the raids this week, police found an IJU manual explaining how to construct the bomb, investigators say.
Morrison worked with Enrico Fermi in Chicago to refine methods to produce plutonium for the "gadget," as it was called, then later moved to Los Alamos to help construct the bomb's core.
Although Mr. Reid told investigators that he had constructed the bombs himself from materials he bought in Europe, prosecutors said they found evidence that he had help.
Reyat was working as a mechanic in westernmost Canada and purchased the dynamite, batteries and detonators used to construct the bombs.
Among the natural scientists (most of whom were instrumental in constructing the atom bomb) were Albert Einstein, Enrico Fermi, Edward Teller, Leo Szilard, and Hans Bethe.
While analogue, punch-card styled computers were still used to calculate the vast numbers of differential equations for constructing the atom bomb, the work at Los Alamos was instrumental in spurring the development of electronic digital computers, with much owed to the theoretical efforts of John von Neumann.
