The Secrets of the Bomb
By Jeremy Bernstein
Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea
by Jeffrey T. Richelson

Norton, 702 pp., $34.95

"What is the answer to the atom bomb? The answer to an atom bomb is an atom bomb, nothing else."

—Atal Bihari Vajpayee, of the Indian BJP, 1996
1.

In 1944, when the atomic project was well underway, if I went to the bar in the La Fonda Hotel in Santa Fe I might have seen some physicists I would recognize. For example, Robert Serber, one of Oppenheimer's closest associates, and his wife were sent to Santa Fe to plant the rumor that what was going on at Los Alamos had to do with submarines. I am not sure how much one would have learned by monitoring their conversations with other physicists, since they used a code when talking about the nuclear bomb project. Uranium-235 was called "25" and plutonium-239 was known as "49." These were the fissionable isotopes. Niels Bohr was known as "Nicholas Baker" and Enrico Fermi was known as "Henry Farmer." Los Alamos was known as "Project Y" and the plutonium bomb was known as the "gadget."

By the fall of 1945, such deceptions would have been futile. All the details involved in making the plutonium bomb, the gadget, were known to the Russians. They were revealed basically by a single agent on the ground— Klaus Fuchs. Fuchs, for example, was able to reveal the secret of making plutonium usable for atomic weapons, a secret the Russians would have had considerable difficulty discovering for themselves. Plutonium is the most complex element in the periodic table. It does not occur naturally, and it has to be not only manufactured but also put into metal form before it can be used in an explosive chain reaction. This is what produced the explosion that took place at Nagasaki. Plutonium comes in at least six different crystalline forms—allotropes—that manifest themselves at different temperatures. At room temperature the so-called alpha phase is found. You can't easily make a metal out of it. On the other hand, at high temperatures there is the delta phase from which you can make a very useful metal; but it relapses to the alpha phase when it cools, so it is very difficult to use.
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At Los Alamos there was a brilliant British-born metallurgist named Cyril Smith who had made a career in the brass business, in which alloys are central to making different products. By trial and error he found that if you alloyed plutonium with gallium it stabilized the delta phase, and you could make a plutonium metal. From that day to this, no one knows why gallium works or what the stability of the alloy is over a very long period, something that is important for storing warheads. The use of this alloy is a crucial bit of information that is absolutely essential in the manufacture of plutonium-based nuclear weapons, and Fuchs was in a position to pass it on. When the Russian physicists learned his identity they nicknamed him Santa Klaus.

Fuchs, the son of a Lutheran minister, had been born in Rüsselsheim, Germany, in 1911. As a student he joined the German Communist Party and when the Nazis came to power he left Germany. He managed to get to Bristol University where he got his Ph.D. in 1937. When the war came, he was interned in Canada as an enemy alien but Max Born, one of his professors, got him released. He was then approached by Rudolf Peierls, who made the first calculation of the "critical mass" needed to make a uranium bomb, to work on nuclear weapons. From the time the Germans invaded Russia, Fuchs began giving information to the Soviets about the bomb. When Peierls joined the British delegation to Los Alamos, Fuchs was asked to go along. Recently, a remarkable letter to Peierls from James Chadwick who headed the British delegation to Los Alamos has emerged, in which he describes Fuchs's reluctance to go. He thought that he could be more useful to the project staying in England. If he had, the subsequent history of the Russian atomic bomb might have been quite different. Once at Los Alamos Fuchs was at the center of the work. He knew everything and transmitted what he knew through the courier named Harry Gold.

The people at Los Alamos liked him. He was a solitary man, worked hard, and was always available as a baby sitter when the more sociable scientists needed one. After the war, the British were not allowed to take classified documents with them. In Fuchs's case it didn't matter, since he had a photographic memory and memorized the final design of the gadget, which he saw tested at Alamogordo. This was the same bomb design that destroyed Nagasaki a month later. In October of 1945, a report was delivered to Lavrenty Beria, whom Stalin had put in charge of the Russian bomb program, spelling all of this out. Of the plutonium it says, "The element plutonium of delta-phase with specific gravity 15.8 is the active material of the atomic bomb."[1] It is equally specific about the rest of the design.

How this information aided the Russians is a matter of some disagreement. Beria did not share it freely with the scientists. He probably did not entirely trust the source. There was at least one other source, a young physicist named Theodore Hall who also transmitted material independently from Los Alamos. The Soviet scientists were given information that surely had an effect. What the spies said about plutonium metallurgy and the use of gallium must have saved months of trial and error.

In any event, the first atomic bomb the Russians tested—which they called "First Lightning" and the US called "Joe 1"—was exploded on August 29, 1949. It was a duplicate of the gadget. The US intelligence services were caught completely off-guard. The Americans had no agent on the ground in the USSR and relied on a monitoring system using aircraft alleged to be on routine weather patrols. The planes were equipped to collect radioactive samples of the kind that a reactor accident or a nuclear explosion would produce. Until this data was collected and analyzed, which took several weeks, there was considerable disbelief—including that of President Truman—that the Russians had really tested an atomic bomb. Once it was verified that they had, the cold war nuclear arms race was on. Fuchs was identified in 1950 and served nine years in prison in Great Britain. He was allowed to return to Germany, and died there in 1988.

The reader may wonder why I have not mentioned the hydrogen bomb and any part that Fuchs might have had in the Soviet program to make it. So much of the relevant information is still classified that it is very difficult to arrive at a complete accounting of his contribution. In the case of the fission bomb this is possible because the relevant material is unclassified. We know that what Fuchs did was to supply the Russians with a blueprint of the plutonium implosion bomb that was tested at Alamogordo and dropped on Nagasaki. The Russians then copied this blueprint. Fuchs left Los Alamos in 1946 to return to England where he had an important part in the development of British nuclear weapons.

This took place before there was a breakthrough in the American hydrogen bomb program, owing to the work in 1951 of Stanislaw Ulam and Edward Teller. Nonetheless, Fuchs had been active in hydrogen bomb work before he left the US. In 1946, he and the Hungarian-born mathematician John von Neumann took out a patent on what they thought was a design for a hydrogen bomb.

Such a bomb gets its energy from the fusion of light elements—possibly but not necessarily hydrogen—to make other light elements, with the consequent release of energy. This is the process that makes stars shine. From the beginning of the war, a number of scientists realized that if this process could be duplicated, one could make a weapon of almost limitless energy. The trick was to heat the fusible elements to temperatures like those of the interior of the sun. This was to be done in two steps by using the energy from a fission bomb. First, one had to "ignite" the fusing light elements; second, once ignited, the fusion reaction had to "propagate"—i.e., maintain the ignited state. This latter process was the hard part, and all the designs up to those of Ulam and Teller resulted in a cooling-off before they could propagate. This problem was not solved by Fuchs and von Neumann, but they did propose a novel form of ignition, which was a forerunner of the Teller-Ulam design, and this is what Fuchs gave to the Russians. There is no consensus on the extent to which the Russians used it; but there is increasing agreement that it was of significant help to their program.

More at

http://www.nybooks.com/articles/19010

I thought of all of this when I read the fascinating new book Spying on the Bomb by Jeffrey T. Richelson, a senior fellow at the privately funded National Security Archive and the author of other books on military intelligence. While some of this material has been available in other sources, it has never been put together so comprehensively. He has also interviewed some of the participants. The book begins with an account of US attempts during World War II to learn what the Germans were doing and goes on to describe its efforts to obtain information about the nuclear programs of the Iraqis, North Koreans, South Africans, Israelis, and Iranians. The one common theme is that if you do not have both agents on the ground and competent people to interpret what they have uncovered, you are playing a game of blindman's bluff with very high stakes indeed.

http://www.nybooks.com/articles/19010

Bot, didja ever get to read "Caging the Dragon"?

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Never a dull moment at Berry Hill Farm.

This?

http://en.wikipedia.org/wiki/Caging_the_Dragon

No I haven't, but Google is my middle name. I'm looking for an online copy but at over 700 pages, I doubt it's up on the web. Also, 700 pages strikes fear in my heart. I have an evil premonition that it's going to be a lot of engineering. That maybe one of (many) books that it takes me over 20 years to read!

I'm thinking about buying Bernstein's book. I have read other things by him and I find his style very engaging and honest. Sort of like Feynmann (with the utter brilliance) but without the satirical wit.

I'm amazed that these secrets have stayed relatively secret for so long. I fear that it's just a matter of time before somebody loses their cool. Even if this civilization continues, maybe it will be neccessary to "demonstrate" - the hard way - one of these every 50-100 years.

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Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm

When we were stupid kids in Tidewater Virginia we would amble down to the hardware store,buy a 2"diax4"long galvanised pipe nipple with 2 end caps and proceed to fill it halfway with Drano crystals,shredded aluminum foil plus a little water,we'd screw the cap on,throw the damned thing as far as possible and wait........generally they would blow within 2-4 minutes.

Great fun in the junkyards as we would chuck'em in defunct autos and watch with rapt attention as the windows would shatter while the roofs would occasionally get pierced by the pipe shrapnel,we later refined this tecnique by using larger pipe nipples with nails packed around the circumference,ahhhh,lost youth!

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