The Los Alamos Primer is a printed version of the first five lectures on the principles of nuclear weapons given to new arrivals at the top-secret Los Alamos laboratory during the Manhattan Project. The five lectures were given by physicist Robert Serber in April 1943. The notes from the lectures which became the Primer were written by Edward Condon.
History
The Los Alamos Primer was composed from five lectures given by the physicist Robert Serber to the newcomers at the Los Alamos Laboratory in April 1943, at the start of the Manhattan Project. The aim of the project was to build the first nuclear bomb, and these lectures were a very concise introduction into the priciples of nuclear weapon design. Serber was a postdoctoral student of J. Robert Oppenheimer, the leader of the Los Alamos Laboratory, and worked with him on the project from the very start. The five lectures were conducted at April 5, 7, 9, 12, and 14, 1943; according to Serber, between 30 and 50 people attended them. Notes were taken by Edward Condon; the Primer is just 24-pages-long. Only 36 copies were printed at the time.
Serber later described the lectures: Previously the people working at the separate universities had no idea of the whole story. They only knew what part they were working on. So somebody had to give them the picture of what it was all about and what the bomb was like, what was known about the theory, and some idea why they needed the various experimental numbers.
In July 1942, Oppenheimer held a "conference" at his office at Berkeley. No records were preserved, but the Primer arose from all the aspects of bomb design discussed there.
Content
The Primer, though only 24-pages-long, consists of 22 sections, divided into chapters:
Preliminaries
Neutrons and the fission process
Critical mass and efficiency
Detonation, pre-detonation, and fizzles
Conclusion
The first paragraph states the intention of the Los Alamos Laboratory during World War II: The object of the project is to produce a practical military weapon in the form of a bomb in which the energy is released by a fast neutron chain reaction in one or more of the materials known to show nuclear fission.
The Primer contained the basic physical principles of nuclear fission, as they were known at the time, and their implications for nuclear weapon design. It suggested a number of possible ways to assemble a critical mass of uranium-235 or plutonium, the most simple being the shooting of a "cylindrical plug" into a sphere of "active material" with a "tamper"—dense material which would reflect neutrons inward and keep the reacting mass together to increase its efficiency (this model, the Primer said, "avoids fancy shapes"). They also explored designs involving spheroids, a primitive form of "implosion" (suggested by Richard C. Tolman), and explored the speculative possibility of "autocatalytic methods" which would increase the efficiency of the bomb as it exploded.
The Primer became designated as the first official Los Alamos technical report (LA-1), and though its information about the physics of fission and weapon design was soon rendered obsolete, it is still considered a fundamental historical document in the history of nuclear weapons. Its contents would be of little use today to someone attempting to build a nuclear weapon, a fact acknowledged by its complete declassification in 1965.
In 1992, an edited version of the Primer with many annotations and explanations by Serber was published with an introduction by Richard Rhodes, who previously published The Making of the Atomic Bomb. The 1992 edition also contains the Frisch–Peierls memorandum, written in 1940 in England.
Reception
The physicist Freeman Dyson, who knew Serber, Oppenheimer, and other participants of the Manhattan Project, called the Primer a "legendary document in the literature of nuclear weapons". He praised "Serber's clear thinking", but harshly criticized the Primers publication, writing "I still wish that it had been allowed to languish in obscurity for another century or two." Acknowledging that it was unclassified in 1965, and that it can't be useful to any bomb designer from 1950, Dyson still thinks that such publication can be dangerous: