Harold Brown and the Linda

#defense #nationalsecurity

Harold Brown

As I hope we’re beginning to see, over the past few blogs including those entitled Legacies and Mr. Innovation, there was a passing of the baton from Lawrence to upstarts of the next generation, physicists like Mike May and Johnny Foster. In this blog, we’re going to see up close one more upstart, and that is Harold Brown. He would become the Secretary of Defense in the Jimmy Carter Administration, but here we’ll be looking at Brown not as a politician, but at what he accomplished as a genuine physicist. Here’s the next blog to highlight a “hopefully” upcoming book From Berkeley to Berlin.

The city of New York has three “magnet high schools:” the Bronx School of Science, Peter Stuyvesant High School, and Brooklyn Tech. These are public high schools, but they’re not open to any New York kid; to get in you had to take an entrance exam along with a gazillion other New York kids wanting to get in, and only the kids with the highest scores got in—kids like Harold Brown. At an early age, it became obvious Brown was exceptionally intelligent. He attended the Bronx School of Science, where he excelled in mathematics and science. At last count, I think I remember that high school graduated five individuals who would go on to win the Nobel Prize—including physicists like Richard Feynman.

By his 22nd birthday, Brown earned his PhD in experimental physics from Columbia University; the chance to participate in physics discoveries drew him to Ernest Lawrence and his Rad Lab in Berkeley. To be honest, I once spent a day with Harold and as I was interviewing him, I assumed he was a theoretical physicist. He quickly set me straight, looked at me and said when he arrived in Berkeley, he was assigned to assist Herb York in designing targets for the MTA project. (You might remember the MTA project is what brought the Rad Lab into Livermore—see the blog How Did Livermore Get Involved Anyway.) We saw in the last blog that following the disaster of the Koon event, Brown and Foster co-wrote a manifesto to the scientists of the Laboratory they were abandoning the research path set by Edward Teller.

So, Harold Brown had to establish a strategic plan on how he was going to lead his group, the Livermore Megaton Group, to design a new kind of thermonuclear warhead. Just as Teller was pushing Johnny Foster to carry on with yet another hydride atomic device, so too, he pushed Brown to test another thermonuclear device that looked very much like the ill-fated Koon device. Harold looked over all the results of the thermonuclear tests of Operation Castle in 1954, and concluded that Los Alamos physicists had established very well their ability to design hydrogen bombs. In a show of independence, he followed through on his earlier declaration and declaring he saw no advantage to pursue yet another Koon-like device, he abandoned Teller’s design.

Harold Brown with Edward Teller with the Livermoer Advanced Research Computer

So, for Operation Teapot in 1955, Brown needed to develop a thermonuclear device that was smaller than the bombs tested a year earlier, since LASL had established quite well that they knew how to design large devices. Just as much as I couldn’t go into details before about nuclear designs, I am going to be careful here as I try to describe what Brown accomplished in the next few months.

Why go after a smaller warhead? It had something to do with one unwritten obligation given to the Laboratory by the AEC when it was created: Brown had to avoid duplicating Los Alamos designs. It also had to do with having a band of RAND analysts working together with the Laboratory physicists. As we’ll learn in a following blog, a national strategic deterrent plan was taking root in Laboratory as a result of the RAND-Livermore collaboration, and that led designers to concentrate on designing thermonuclear devices that were much smaller than earlier devices.

When Herb York worked at Eniwetok Atoll for the George event in 1951, Teller paid a visit to him, and on a blackboard in a Quonset hut, Teller drew for York a design that would become the design of the Mike device, the world’s first hydrogen bomb. York looked over Teller’s drawing, saw how it worked, and started to think how he would go about his own design for a thermonuclear device. As I was researching this history, I read through the minutes of biweekly classified meetings York held with a steering group he formed after the creation of the Laboratory, and the physicist secretary who recorded the meetings was excellent in capturing everything said. At the second such meeting, York drew on a blackboard his idea for modifying the Teller-Ulam design for a thermonuclear device. What York did was quite an accomplishment since his drawing was made two months before a thermonuclear device existed.

Now, as Brown was preparing for Operation Teapot, he cloistered himself with York, and the two highly talented physicists developed a design for a thermonuclear weapon that was radical. I’m trying hard not to trivialize the word “radical,” since I emphasized in my last blog that Johnny Foster had developed an atomic device that was unprecedented. Nevertheless, what Brown came out with after sequestering himself with York is simply astounding. The new design would be only a fraction the size and weight of a typical thermonuclear device of the time.

Following the same protocol that led Johnny Foster to give his atomic device a female name, the Cleo, Brown named his new thermonuclear device the Linda. The Linda was small; it would be the smallest thermonuclear device tested up to that time. Now remember, a thermonuclear device is triggered by an atomic device that radiates energy into thermonuclear fuel until it reaches an ignition temperature. In the jargon of nuclear weapon designers, the atomic device is called a primary and the thermonuclear device is called a secondary. At the time the Linda was going to undergo a nuclear test, the Laboratory had not yet tested a primary that could be reliably counted on to drive a secondary, so the Megaton Group designers chose a Los Alamos primary to drive the Linda.

A couple of weeks after the successful test of the Cleo, a 500-foot tower was set up for testing the Linda. It was detonated on schedule, and its yield was measured to be almost exactly as had been predicted. Brown said before the test that if the Linda succeeded, it would affect the design of future thermonuclear devices. Brown was more prescient than he could have imagined. I said I’d be careful using the word radical, and I will, but the moment the Linda went off, thermonuclear devices tested prior to it could be considered to be obsolete—the Linda was that radical. The Linda would start a chain of designs that would become America’s modern thermonuclear device. The statements I just made I understand would be considered controversial in many quarters—so be it; I can defend them.

Brown had been faced with a dramatic do-or-die situation as Operation Teapot approached. The Koon test, being a total fizzle, had set up the Laboratory to make it look like the government’s decision to establish a second nuclear weapons laboratory was a mistake. If Brown’s device failed, there would not be another chance. He, his group, and his laboratory, would be disgraced. And yet, Brown didn’t opt to repeat a design from Los Alamos that been shown to work, and instead he chose to design a thermonuclear device that was revolutionary. He was yet another upstart who did good.

This was all happening in 1955, and these events, the tests of the Cleo and the Linda, were momentous. I thought back to that year and considered what else was happening. Marilyn Monroe was hitting her prime, and rock and roll was the music of the land. Clearly though, what really set 1955 apart, was not only Operation Teapot, but it was the year when the Brooklyn Dodgers finally beat the New York Yankees in the World Series. It’s important to keep these things in perspective.

7 thoughts on “Harold Brown and the Linda

    1. Tom Ramos

      Thank you Bill, you’re right, I’m too familiar with the subject and assume everyone reading the blog should already know all details. So, the MTA, the Mass Test Accelerator, was intended to be a machine to produce the element tritium, which Lawrence wanted to produce after hearing from Ulam the Super project needed it. The idea was this: accelerate deuterons, deuterium nuclei, in an accelerator, the MTA, and have them strike any heavy metal, like a brick of tungsten. The deuterons cause nuclear reactions in the tungsten that release neutrons, so now you have a shower of neutrons. The neutrons can now strike “targets” like lithium or other light metals, and those reactions are what will produce the tritium. So, Brown and York were experimenting with target designs that could effectively produce tritium out of a stream of neutrons.

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      1. Tom Ramos

        Harold told me he was an experimentalist. He and York would design a target then conduct an experiment with it to see how much tritium they created.

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  1. Harry C Vantine

    Great storyline, Tom. You really set it up well, with the failures at the Rad Lab followed by the new wave. It is often the passing of the torch to the next generation that does this in science.

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    1. Tom Ramos Post author

      Thanks Harry. What intrigued me very much was that Lawrence kept with them. They, the upstarts, were now leading the charge, but he kept encouraging them, and behind the scenes, made things happen. He sure knew how to pick leaders, didn’t he.

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