The Los Alamos Primer

los_alamos-primerThe subtitle of this book is “The First Lectures on How to Build an Atomic Bomb.” The book was annotated by Robert Serber and edited with an introduction by Richard Rhodes. It is a fascinating book that would take a long time to fully digest despite its length (only 98 pages including Appendices, Biographical Notes, and an index. The Biographical Notes includes many of the “famous scientists of the times,” but not Robert Serber. I enjoyed the book because it wove the very complicated scientific developments with refreshing non-technical descriptions and comments that made me feel less intimidated about the brilliance of what was being described. The descriptions were often “clipped,” which means it didn’t always flow as well as what you would expect from a literature major. Perhaps that is because the author was a physicist. Some of my favorite passages involve Charlotte Serber (who also is sadly not listed in the index), Robert Serber’s wife. For example, she is described as being the librarian for the project before there were books. I thought about buying a copy for each of our grandsons who are interested in science. However, I admit that I was a bit intimidated by the $40-$60 price for the used books. I suggest you request your local library to borrow it from a local university, which is what I did.

I’ve selected a few snippets from the introduction by Richard Rhodes. Young scientists began arriving in New Mexico to work on a project they were told could end the war. They knew they would be behind barbed wire and cut off from the world. They knew they would be governed by a blanket of secrecy, but “…unofficially they whispered that they had signed on to attempt nothing less than inventing, designing, assembling the world’s first atomic bombs…” “Signing on to invent and craft new weapons of unprecedented destructiveness may seem bloodthirsty from today’s long perspective of limited war and nuclear truce. Those were different times. War was general throughout the world, a pandemic of manmade death.” ix Churchill used the postwar phrase, “a miracle of deliverance.”

The volunteers were driven in olive drab staff cars into northwest New Mexico onto a plateau from “…the collapsed cone of the largest extinct volcano in the world. Los Alamos, the mesa was called, named for the cottonwoods that grew in the steep canyons…” The physicists called their location “the Hill.”

Robert Serber was an Oppenheimer protégé, and he was selected to begin the work of the secret project with a series of lectures. He had guided a secret seminar at Berkley the previous summer, and therefore had explored the ideas he would discuss. “The object of the project is to produce a practical military weapon in the form of a bomb in which energy is released by a fast neutron chain reaction in one or more of the materials known to show nuclear fission.” Bob Serber delivered five lectures while Edward Condon, the associate director of the lab, kept notes. Condon and Serber worked the notes into what they titled the Los Alamos Primer, and each scientist was handed a copy when they arrived. The population was doubling every nine months until it numbered five thousand by August 1945 when the war ended. The Primer and the Frisch-Peierls memorandum of early 1940 that is included as an appendix “…carry a greater freight of historic import than perhaps any other documents in the history of technology.”

Lise Meitner, Otto Hahn, and Fritz Strassman, an Austrian physicist and two German chemists, made the discovery that led to the bomb. Meitner, who had a Jewish background, had escaped from Germany to Sweden. Hahn and Strassman had found bombarding uranium nitrate with low-energy neutrons had produced barium as a product, and they turned to Meitner for interpretation. She and Otto Robert Frisch, her nephew, tried to imagine a mechanism that could have created the results. Meitner declared that fission had occurred and she named it based on the biological process of cells dividing. Hahn and Strassman published their results in a German scientific journal in January 1939 and Meitner and Frisch followed up with letters to the British Journal Nature. “Within a year more than one hundred papers had appeared on the new reaction, reporting work by physicists throughout the world.”

Physicists everywhere recognized that nuclear fission could serve as the basis of new sources of power and weapons of war. The Germans convened a secret conference April 29, 1939 that led to a research program and a ban on uranium exports. A Japanese army general ordered exploration of military applications. Leo Szilard, Edward Teller, and Eugene Wigner managed to communicate their concerns about a German program in a letter from Albert Einstein that President Roosevelt reviewed on October 11, 1939. The British took a first look in 1939 and began to consider it again in early 1940. Igor Kurchatov alerted the Soviets of the possibilities in 1939.

There were several problems the Manhattan Project had to solve. Critical masses had to be determined for U235 and plutonium without blowing everything up. Metallurgy of both materials had to be determined. A neutron initiator had to be invented. Few knew anything about explosives, and new technology that allowed explosives to be precision instruments had to be developed. Bombs had to be small enough to fit into a bomber that could still take off with the weight. Bomb casings to contain what was called the Gadget had to be manufactured.

The first shipments of plutonium from the reactors at Oak Ridge revealed there was too much Pu240 to allow the “plutonium gun design” to work: the Pu240 would cause pre-detonation before the critical mass needed for an atomic explosion could be created. The discovery led to a crisis that required reorganization and refocus on development of an implosion method. John von Neumann designed an explosive lens that would redirect the blast inward. Edward Teller contributed that an implosion could compress metal, which would make a supercritical mass.

For those who disagree with or wonder about Truman’s decision to drop the bomb, He had appointed a panel of scientists, including Oppenheimer, to advise on whether to use the bomb in a “demonstration” on an uninhabited area. The panel advised, “We can propose no technical demonstration likely to bring an end to the war; we see no acceptable alternative to direct military use.”

The story of how Robert Serber became the one to give the lectures that would become the Los Alamos Primer begins in the Preface, which Serber writes in the first person. He says he had gone to work in Berkley and “…bumped into Oppy—Opje, we called him then, the Dutch version of his nickname. Serber describes the wanderings of he and his wife Charlotte to a variety of research centers where he connected with a long list of people who would become famous in physics.

There were some fifty people assembled in the library reading room for the lectures and there was hammering all around as workmen were building facilities. At one point a leg came bursting through the ceiling. Serber started talking and mentioned the “bomb.” Oppie sent John Manley up to tell him not to use that word, and he began using the term “gadget.” Condon recorded both words, but in Los Alamos after that the bomb being built was called the gadget.

The book is both interesting and at times entertaining. For example, Serber mentions they could have ordered a bucket of diamonds and they would have received the order. Charlotte, the librarian, did have an 80 pound sphere of gold and a 60 lb of platinum that had been ordered and delivered. There is no mention of why they were needed.

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