''The Los Alamos Primer'' was a printed version of the first five lectures on the principles of

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...

s given to new arrivals at the top-secret

Los Alamos laboratory The Los Alamos Laboratory, also known as Project Y, was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II. Its mission was to design and build the first atomic bombs. Ro ...

during the

Manhattan Project The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...

. They were originally given by the physicist

Robert Serber Robert Serber (March 14, 1909 – June 1, 1997) was an American physicist who participated in the Manhattan Project. Serber's lectures explaining the basic principles and goals of the project were printed and supplied to all incoming scientific st ...

after being delivered in person on April 5–14, 1943, based on conclusions reached at a conference held in July and September 1942 at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

Robert Oppenheimer J. Robert Oppenheimer (; April 22, 1904 – February 18, 1967) was an American theoretical physicist. A professor of physics at the University of California, Berkeley, Oppenheimer was the wartime head of the Los Alamos Laboratory and is often ...

. The notes from the lecture which became the ''Primer'' were written by

Edward Condon Edward Uhler Condon (March 2, 1902 – March 26, 1974) was an American nuclear physicist, a pioneer in quantum mechanics, and a participant during World War II in the development of radar and, very briefly, of nuclear weapons as part of the ...

. The first paragraph states the intention of the Los Alamos laboratory during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

: :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 Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: * pure fission weapons, the simplest and least technically ...

. It suggested a number of possible ways to assemble a

critical mass In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fi ...

uranium-235 Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exi ...

plutonium Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibi ...

, 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

spheroid A spheroid, also known as an ellipsoid of revolution or rotational ellipsoid, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters. A spheroid has ...

s, 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 Nuclear weapons possess enormous destructive power from nuclear fission or combined fission and fusion reactions. Building on scientific breakthroughs made during the 1930s, the United States, the United Kingdom, Canada, and free France collabora ...

. 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. It used to be available for download from Los Alamos's website, but after the

September 11 attacks The September 11 attacks, commonly known as 9/11, were four coordinated suicide terrorist attacks carried out by al-Qaeda against the United States on Tuesday, September 11, 2001. That morning, nineteen terrorists hijacked four commer ...

, Los Alamos restricted access to all of their technical reports. It can still be found on internet mirrors, though, as well as on Wikipedia. In 1992, an edited version of the ''Primer'' with many annotations and explanations by Serber was published with an introduction by

Richard Rhodes Richard Lee Rhodes (born July 4, 1937) is an American historian, journalist, and author of both fiction and non-fiction, including the Pulitzer Prize-winning ''The Making of the Atomic Bomb'' (1986), and most recently, ''Energy: A Human Histor ...

References

*Serber, Robert. ''The Los Alamos primer: the first lectures on how to build an atomic bomb'', edited with an introduction by Richard Rhodes. Berkeley: University of California Press, 1992.

External links

The original ''Los Alamos Primer'' (LA-1)
from a Federation of American Scientists mirror
A mirror of the FAS file at Wikimedia CommonsReview of the 1992 version of the ''Primer''
{{Authority control Manhattan Project Books about the Manhattan Project 1943 non-fiction books Books of lectures History of physics

See also

References

External links