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Even as he chided Lawrence for overoptimism, Groves, too, had begun thinking beyond the war’s end. As early as spring 1944, he had asked Princeton physicist Henry Smyth to begin writing a technical history of the Manhattan Project that could be publicly distributed after the war. Smyth’s report was intended, in part, to be a vindication of the project’s cost and effort; as such, it was really Groves’s valedictory. But the report was also a tidy and convenient way of dividing what scientists could talk about from what had to remain officially secret.
In August, Bush picked Richard Tolman to head a panel that would make recommendations on postwar atomic research, including its applications to industry.39
Two weeks later, Tolman’s Committee on Postwar Policy interviewed almost fifty Manhattan Project scientists in Chicago, New York, and Washington, D.C.40 In a written response, sent from Los Alamos, Oppenheimer focused on the hydrogen superbomb and a hybrid fission-fusion device, the “Booster,” which Teller had proposed at the lab late in 1943. But Oppie thought it likely that both the Super and the Booster would remain essentially unexplored at war’s end: “I should like, therefore, to put in writing at an early date the recommendation that the subject of initiating violent thermo-nuclear reactions be pursued with vigor and diligence, and promptly.”41
Lawrence planned a different path: he looked to the government as the engine that would drive and even accelerate postwar scientific research at Berkeley. But he also envisioned an improved, fully automated, peacetime Y-12 producing enriched uranium at five times the wartime rate.42
Meeting with Tolman’s committee on Wednesday morning, November 8, 1944, at the National Academy of Sciences in Washington, Lawrence spoke of a ten-fold increase in output from the latest version of his Calutron, the Alpha III. Ernest envisioned each future racetrack churning out not only U-235 but also low-grade uranium fuel for the atomic reactors that would generate the electricity to run the plant, in what amounted to a kind of self-sustaining perpetual motion machine. “There must be a postwar policy and program on a very large scale,” he declared. “It can’t be piddling.”43
When Oppenheimer appeared before Tolman’s committee that afternoon, a more reflective mood prevailed. Oppie declared that wartime secrecy was antithetical to maintaining the country’s “technical hegemony” in peacetime. “If we try to work in secret after the war, we will fall behind other countries better able to work in secret,” he warned.44
Characteristically, Lawrence had already begun laying the groundwork for his postwar plan. Before returning to California, he and Cooksey stopped off at Groves’s Washington office to plead for construction of a new electromagnetic separation plant after the war.45 Lawrence wanted the army to look at abandoned smelters near Las Vegas, Nevada, and in Washington State as possible sites for a reborn Y-12.46 Another facility was urgently necessary, Ernest argued, because existing equipment was obsolete and the machinery breaking down: the copper liners of the Alpha Calutrons were already wearing out.47
To Lawrence’s great disappointment, Tolman’s report—given to Groves just after Christmas—failed to make a case for the new Calutrons.48 But even more disturbing to Ernest was a rumor that Oppenheimer had been one of those to speak out against his plans.49 When Lawrence had last raised the issue of plant expansion with his old friend, Oppie had seemed supportive.50
By February 1945, Lawrence was still anxiously awaiting a final decision by Groves on the fate of his proposal. In a telephone call at the end of the month, the verdict was relayed by Fidler: the Calutrons had served their purpose; the army would pay for no more following the conclusion of the war.51
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A few days earlier, the design of Little Boy had been frozen at Los Alamos. The uranium gun was expected to be ready for combat use by July.52 Groves tentatively scheduled a test of the implosion bomb for Independence Day, in the New Mexican desert near Alamogordo, 200 miles south of Los Alamos.53
For reasons that Oppenheimer decided to keep obscure, he had named the test site Trinity—a secret tribute to Jean Tatlock, who had committed suicide at her San Francisco apartment in January 1944.*54
At Oak Ridge, meanwhile, the gaseous diffusion plant known as K-25 was producing enriched uranium at nearly bomb-grade concentrations, making further processing by the Alpha Calutrons unnecessary. The end product from the cascades was now fed directly into the Beta machines. Because of these additional sources, another milestone was reached that spring: the output of U-235 in March again exceeded production for all previous months combined.55
The gathering momentum at both Y-12 and Los Alamos meant that Germany’s surrender in early May had little impact upon the Manhattan Project. Despite Robert Wilson’s attempt to raise the question of whether their efforts should continue, only one scientist at the lab—a member of the British delegation—elected to quit before the Japanese enemy was defeated. The thrumming of Lawrence’s Calutrons continued uninterrupted. As Pash’s Alsos mission had found that spring, the country where fission was discovered never came close to harnessing it for a bomb.
In another subtle sign that the drama was approaching its climax, Groves lifted the ban that had grounded laboratory directors. The army informed Tennessee Eastman of pending reductions in the workforce at Oak Ridge, while Lawrence was told to trim nonresearch personnel at the Rad Lab by 20 percent.56 The previous summer, Underhill had advised Oppenheimer that the university was preparing to “taper off” its commitment to run Los Alamos and hoped to be out of the bomb business altogether by the end of the war.57
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As the Manhattan Project picked up speed, so, too, did Soviet efforts
