McMillan and Segrè were engaged in a search for as-yet-undiscovered fissionable elements, farther up the periodic chart than uranium. Abelson, now at Washington’s Carnegie Institution, returned to Berkeley that spring for a brief working vacation to help out. By bombarding uranium with neutrons in the 60-inch, Abelson and McMillan created a previously unknown and unstable transuranic with an atomic number of 93. It decayed after two days to a stable new element with an atomic number of 94. Following the convention, McMillan named element 93 “neptunium,” for the planet next in line after Uranus. Abelson’s vacation ended before he and McMillan could prove the existence of element 94, so it remained unnamed. Since neptunium had many of the same properties as uranium, however, both it and the mysterious 94 seemed logical candidates for fission.69
On the same day in June 1940 that Abelson and McMillan announced their discovery in the Physical Review, the Germans entered Paris.
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The Hungarians were not the only ones frustrated at the somnolent pace of Briggs’s Uranium Committee. Bush, Conant, and Karl Compton joined with National Academy of Sciences’s president Frank Jewett later that month to lobby for an organization that would mobilize America’s scientific manpower. Headed by Bush, the National Defense Research Committee would become the dynamo behind technical ideas aimed at helping win the war, if and when America entered the conflict.
Bush moved quickly to have the NDRC assume oversight of Briggs and the Uranium Committee.70 Although it was too late to keep Berkeley’s discovery of neptunium under wraps, Bush suggested a voluntary moratorium upon the publication of scientific papers dealing with uranium and fission. By informal agreement among the scientists themselves rather than by government fiat, the age of discovery in high-energy physics had come to an end, at least for the duration.
Lawrence returned to the Rad Lab from vacation in August, disappointed that so little progress had been made in atomic research during his absence. Nonetheless, he remained unwilling to take a more direct role in preparing the nation for war.71 Ernest also brushed off an appeal from Columbia University chemist Harold Urey that he join in endorsing the interventionist cause.72
A few days later, Bush tried another approach: flattery.73 He hoped to recruit him to head “a sort of fire department,” Bush wrote Lawrence, emphasizing that he would not have to abandon his work at the Rad Lab.74 The kind of organization that Bush had in mind would have started fires under recalcitrant research problems, not put them out. But, while Lawrence agreed on the need for such an effort, Bush himself abandoned the idea when Ernest pointed out that senior scientists would surely object to reporting to a younger man.75
On October 2, 1940, Bush telegraphed Lawrence again, this time with a single urgent question: “When could you come for conferences important matter?”76
The meeting to which Lawrence was summoned dealt not with the atomic bomb but with a new British invention: microwave radar. It took place over the weekend of October 12–13 at Alfred Loomis’s mansion-laboratory. Bush, Karl Compton, and the Cavendish’s John Cockcroft also attended. Loomis was the logical host, since his institute had done some of the earliest work in the country on radar detection. (Loomis’s colleagues had invented the world’s first portable radar gun, successfully testing it the previous summer on unsuspecting motorists traveling a nearby highway. “For the Lord’s sake, don’t let the cops know about this,” one researcher reportedly warned.)77
Of immediate interest to the British, of course, was using radar to detect and intercept the German bombers that were then attacking London in the Blitz. While the key invention, the cavity magnetron, came from a laboratory in England, the British wisely realized that their wealthy American cousins had a better chance of improving radar in time for it to make a difference in the war.
The group chose a site at MIT for the radar work, giving it the deliberately misleading title “Radiation Laboratory” in hopes of deceiving Nazi spies. Lawrence resisted Loomis’s appeal that he head the enterprise. Instead, Ernest picked its director, Rochester University physicist Lee DuBridge, a Lawrence protégé, and further demonstrated his commitment to the cause by volunteering two of his best scientists, McMillan and Alvarez, for the East Coast Rad Lab. By November, the duo was already on their way to Cambridge. Oppenheimer gave each a bottle of whiskey as a going-away gift; Cooksey arranged for the university’s brass band to serenade the departing heroes on the train platform.78
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The reason for Lawrence’s reluctance to personally take part in the scientific mobilization for which he had become a willing recruiter was already beginning to take shape on the land above campus. In August, construction had begun of the steep road that would wind up Charter Hill to the site of the 184-inch. Early that October, the 1,000-ton concrete base for the cyclotron was poured. The first shipment of steel was trucked up to the construction site at the end of the month. By November, the metal skeleton of the distinctive twenty-four-sided building that would house the machine had begun to go up.79
Following McMillan’s departure, the job of identifying the properties of element 94 had been taken over by Seaborg and Segrè. In December, while at Columbia University on a recruiting drive for MIT’s radar lab, Lawrence volunteered use of the 60-inch to create enough of the element for experiments.
Because of the war, funding at least had ceased to be a problem for Berkeley’s Rad Lab. No longer was Lawrence’s enterprise dependent upon the largesse of foundations and grants from philanthropists. By underwriting the investigation into elements 93 and 94, the NDRC supplemented the Rad Lab’s budget with monies from another and most welcome source: the federal government.
The change was both sudden and apparent. “This war is achieving alterations we would never have seen under other circumstances,” Kamen wrote to McMillan at MIT.80 Depression-era parsimony had ended. Given free rein to purchase equipment from
