Oppenheimer had likewise continued to irritate and embarrass the air force by his advice. Asked by LeBaron to update the 1948 study on long-range military objectives, Oppie’s new panel described the superbomb as “more uncertain and much more difficult of development” than originally believed and, pointedly, a “long range undertaking.”24 The report also put more emphasis upon small, tactical fission weapons—whose development was being hindered by the attention given the Super, Oppie argued.25 Enraged by what he saw as a covert war against the air force’s weapon of choice, Chief of Staff Hoyt Vandenberg ordered Oppenheimer barred from participating in a planned study of strategic targeting.26
* * *
Upon the GAC’s recommendation, the commission decided to withhold funds for Lawrence’s production accelerator, the Mark II, until the prototype machine had been shown to work. Ernest had meanwhile found a site for his Mark I MTA at an abandoned Naval Air Station in Livermore, a verdant valley of farms and vineyards some 40 miles southeast of Berkeley. An Olympic-size swimming pool, once used to train naval aviators in ditching techniques, would provide cooling water for the big machine. High-tension lines that crisscrossed the sere hills, carrying power generated by melting Sierra snows, supplied the electricity. Leftover barracks were pressed into service as offices for scientists and engineers.27
Lawrence had put Alvarez in charge of the MTA. Embracing the project as a surrogate for the ill-fated Benicia Laboratory, Luie imbued it with an enthusiasm that was given added urgency by the Korean invasion. “Anyone who now takes the time to work on mesons is little less than a traitor,” Alvarez reportedly lectured his Rad Lab colleagues.28
Ernest appointed Pief Panofsky the head designer of the machine.29 Lawrence assigned two Rad Lab veterans, Robert Serber and Herbert York, and a relative newcomer—physicist Harold Brown—the task of calculating how many neutrons the MTA would produce.30
But the lab’s focus upon the MTA came at a price: construction of the Bevatron at Berkeley was put on hold. Desks for those assigned to the Livermore project were moved into the building that housed the partially finished machine. Pitzer informed the AEC that, for the foreseeable future, half the Rad Lab’s effort would be devoted to the MTA.31
Like the Calutrons, Lawrence’s latest machine operated at the far edge of the attainable. The Mark I’s cylindrical tank—nearly 90 feet long, 60 feet wide—was the largest vacuum chamber built thus far. Standard-gauge railroad tracks were laid down its middle to move the MTA’s eighteen massive oscillator tubes, the largest of which weighed 40 tons. The electrical power they required would supply a town of 20,000.32
But the Mark I was lilliputian compared to the planned production machine. The Mark II would require concrete walls some 80 feet high and 20 feet thick for radiation shielding alone, and its appetite for water as well as power far outstripped what was available at Livermore.33 Ernest had scouted out a promising site for the Mark II on the banks of the Missouri River, not far from St. Louis. By late August, he was talking about building up to ten of the mammoth machines in the Midwest. When he encountered resistance to his plans at the AEC, Ernest turned to the Joint Committee.34 His enthusiasm had found a match in Borden’s ambition.
Under pressure from McMahon, the commission gave tentative approval for construction of a single Mark II in September 1950, while the prototype machine was still being built at Livermore.35
But only days after the Mark I was completed that fall, it became clear that the MTA project was already in trouble. The most vexing problem was sparking, caused by dust particles in the cavernous vacuum tank and imperfections in its copper lining.36 Moving cots into the barracks, Alvarez and a colleague began working eighteen-hour shifts: Luie polished the shiny lining while his coworker, crawling out onto a wooden latticework some 30 feet in the air, looked for electrical shorts in the oscillator tubes. Retreating afterward to the control room, the two men held their breath while Alvarez gradually increased the power settings.37
Every spark was accompanied by a bright flash of light from portholes in the side of the vacuum tank and a resounding report. Since the sparking pitted the copper, each discharge made the problem worse. In the ensuing silence and stink of ozone came the dawning realization that the tedious process of polishing and testing had to begin anew.38
Throughout the fall and into the winter, brilliant flashes of artificial lightning lit up Alvarez’s control room while crackling thunder rolled across the former navy base.
* * *
Those whom Lawrence had counted upon in the past to fix the problems with his big machines—the theoretical physicists—were gone; the victims, direct or indirect, of the loyalty oath.
Complaining to Sproul of the “almost complete cessation of scientific work of high quality” as a result of the controversy, Panofsky left Berkeley for Stanford that spring. A last-minute effort by Lawrence and Alvarez to change his mind—they arranged a luncheon at Neylan’s Woodside estate, where the regent proceeded to lecture the diminutive physicist on patriotism—only hastened Panofsky’s departure. Seaborg thought the loss “catastrophic” for the physics department.39
Serber was next to go. Berkeley’s remaining theorist told Lawrence he was leaving for “family reasons” only because the truth was too painful to tell. (“It was whether loyalty to Oppenheimer or loyalty to Ernest Lawrence would prevail,” he said, years later.) “Birge, as you can imagine, is quite broken up at the thought of what is happening to his department—telling him was the hardest part,” the shy physicist wrote to Oppenheimer at Princeton.40
Another Berkeley veteran, Emilio Segrè, had already taken a job at Urbana. Segrè’s complaint was not only the oath, he told Sproul, but the “high-handed position” of Alvarez—who “thinks that all the time of the Department should be spent on war work.”41
Before leaving Berkeley, Segrè had tried to tell Lawrence what Serber and others had been hinting at
