mercy. What was, was, and now I am prepared to pay the price.” Fourteen years later, paying the price, he responded from prison to a charge that the judge who appointed his counsel (a distinguished Republican) was indulging a sardonic joke. “Having met Judge McGranery in his professional capacity, as one might say,” Harry Gold wrote his attorney, “… I've never been able to find anything funny in the thirty-year sentence he gave me.” When he got out, Harry hoped to devote the rest of his life to medical research.
24
Mike
The team that Marshall Holloway assembled to design and build the first megaton-scale thermonuclear — the Panda Committee, also known as the Theoretical Megaton Group — met for the first time on October 5,1951, two days after the White House announced the detection of a second Soviet atomic-bomb explosion.[45] Edward Teller's final argument with Holloway before the volatile Hungarian resigned from Los Alamos had concerned how quickly the laboratory could mount a test of the equilibrium thermonuclear. Teller insisted on a target date of July 1952; Holloway held out for late October, partly because he knew how much fabrication and engineering the shot would take, partly because summer was monsoon time in the Marshall Islands. The Panda Committee had a little more than a year to design and deliver a first experimental H- bomb.
One early and important decision concerned which thermonuclear fuel to use. Lithium deuteride was one choice. Deuterated ammonia was another. Liquid deuterium was a third. Each had its advantages and disadvantages. Lithium deuteride — LiD — would be the simplest material to engineer because it was a solid at room temperature, but breeding tritium within a bomb from lithium required a complex chain of thermonuclear reactions that involved only one of lithium's several isotopes, Li6. “We were very much aware of lithium deuteride,” Hans Bethe comments. “We were not totally sure how well it would work.” It was clearly a material that might be tried once the principles of the equilibrium thermonuclear had been proved and the laboratory was proceeding to weaponize the device; Teller and Frederic de Hoffmann had published a technical report, “Effectiveness of Li6 in an ‘equilibrium Super,’” the previous June.
Deuterated ammonia was a liquid at room temperature, but like LiD, its physical properties were not well known. Los Alamos knew a great deal about the physics of pure deuterium, having measured the relevant cross sections and even having observed D fusing with D and with tritium in the
Holloway's team soon settled on liquid deuterium despite its engineering challenges, Carson Mark reports, primarily because it would give the cleanest physics:
In the cryogenic design you had nothing but deuterium — essentially an infinite medium of deuterons [i.e., deuterium nuclei]. With lithium deuter-ide there were as many lithium atoms as there were deuterons, but we were interested in the deuteron reaction, D + D. There wasn't a prominent reaction of deuterium with lithium. The lithium was inert in that respect. In fact it was a diluent. And certainly a complication. And the cryogenic pattern avoided that complication. It introduced some physical complications in construction, in handling, but those one knew how to deal with. They had nothing to do with any of the thermonuclear behavior… The great virtue of lithium, of course, is that it provides you with a free source of tritons [i.e., tritium nuclei]. That's only really true of the isotope Li6. We didn't have large quantities of separated lithium isotopes. We set out to get them and by 1954 we had them. We could have had them earlier if we had known enough to go after them. The description of the [thermonuclear] burning process of pure deuterium is much simpler than the description of the burning process with either Li6 or normal lithium deuteride. The description of the compression of liquid deuterium is simpler than of the compound, the deuteride. To avoid discussing the lithium seemed like a virtue. Every departure from the simplest picture seemed like something to avoid.
Jacob Wechsler, a creative, indefatigable engineer from New Jersey trained at Cornell and Ohio State, worked as one of Holloway's deputies. Wechsler had first come to Los Alamos as a Special Engineering Detachment enlisted man during the war, had gone away to Ohio State for his master's degree in 1947 and then had returned to the lab and gained experience at
One key was setting a time scale early in the game. They said, it may be unrealistic but let's set it and not keep saying, Oh, we've got to slip it. Let's target and try to make it go. That required some real good thinking — namely, what is it you're trying to do in this test? Is it going to be weapon? Is it “proof of principle”? What's it going to be? That was the big discussion. Should it be something that merely demonstrated the principle, so that once we understood the geometry we could try to imagine where we might go from there? That could be a trap. It could be just a wild experiment. How far should you go, how conservative should you be? It's a tough decision because it's a brand new ball game. We had meetings weekly of people from the theoretical division, from the explosives division, from the applied weapons division. The key people had to show up because communications weren't good in those days. You didn't have Xeroxes, you didn't have computers, you couldn't talk over the phone [because phones were not secure].
Devising a system for getting the minutes of Panda Committee meetings out and around the lab in an era when reproducing documents meant using either carbon paper or wax-stencil mimeograph was an important early achievement.
It was clear from the beginning that the test device would be large, since it would have to accommodate a fission primary at one end: the smallest fission bomb available of sufficient yield was forty-five inches in diameter, almost four feet. The complicated device needed thick walls of dense metal to hold it together long enough for a good burn to proceed. Steel was the metal of choice. Who could fabricate thick pieces of steel more than four feet in diameter? Whoever it was would have to be security-checked and cleared. The biggest heavy-equipment manufacturer in the United States was American Car and Foundry of Buffalo, New York, which had built blockbuster bomb casings for the US Air Force for use in Korea. Los Alamos began negotiations with ACF in October aimed at initiating engineering design; ACF started fabrication before the end of the month.
The same problem that plagued Panda meetings plagued engineering design: how to communicate effectively, how to prepare and distribute design changes as the test device evolved. “Marshall finally got the idea that we would make a full-scale drawing of this huge beast,” Wechsler recalls. “Not a working drawing. A schematic. You wouldn't be able to fabricate anything from it, but it would have the kind of dimensions you'd use when you were doing calculations and wanted to know the spacing and thicknesses of the various materials. The idea was to have something where people could come and look and really see what was going on as we added things in. And everybody said, you're nuts. I mean, this gadget is huge. It's six feet in diameter and twenty feet long.” Holloway proposed setting up a giant drafting board in a secure area of the laboratory and putting ACF in charge of maintaining it. For a location, he chose the old Los Alamos Tech Area S building, at the east end of Trinity Drive across from the local dry cleaners. “So ACF built a whole bunch of long sawhorses,” Wechsler remembers, “and we put down sheets of plywood to make an area big enough to put the whole drawing on. The guys who were doing the drawing crawled around in their socks filling things in.”
The drawing was too big to see from the working floor. Holloway had a balcony built inside S building. “You
