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Los Alamos National Laboratory Established, 1943

By Michael Ann Sullivan

In November of 1943, the United States Army chose Los Alamos, New Mexico, as the site of the central laboratory for the top-secret Manhattan Project. President Franklin Delano Roosevelt created the Manhattan Engineering District (MED) during War World II (WWII) to develop an atomic weapon for use during the war. Atomic research in the U.S. began as early as 1939, after refugee scientists from Nazi Germany briefed President Roosevelt on the possibility that Hitler might be developing an atomic weapon for use against the Allies. Roosevelt, persuaded by the eminent physicists Albert Einstein and Leo Slizard, allocated precious resources during the depression years for the pursuit of atomic research. The Japanese attack on Pearl Harbor, in 1941, and the U.S. entrance into WWII intensified efforts to develop an atomic weapon ahead of the Axis.

General Leslie R. Groves oversaw and managed the far-flung activities of the Manhattan Project which consisted of five separate approaches to the development of fissionable material for use in an atomic bomb. Manhattan Project facilities existed at the University of California, Berkeley; the University of Chicago; the Massachusetts Institute of Technology; Hanford, Washington; and Oak Ridge, Tennessee. Even some American industrialists became involved in the secret project. Du Pont, Eastman-Kodak, and other businesses, with particular expertise to lend, researched certain aspects of the mission. Groves insisted on strict compartmentalization of tasks so that very few people knew the nature of the mission.

One of the pitfalls of secrecy was duplication of effort. In 1943, Groves met J. Robert Oppenheimer, a theoretical physicist at Berkeley. Oppenheimer suggested the creation of a central laboratory to co-ordinate all the different approaches to designing an atomic weapon. The idea appealed to Groves and he selected Oppenheimer to recruit scientists and manage such a facility. Oppenheimer accepted and began touring the country recruiting scientists and engineers to work for him. Many of the civilian scientists that accepted Oppenheimer’s proposal had escaped from Nazi Germany or other fascist regimes in Europe. The brightest minds in physics—Niels Bohr, Enrico Fermi, Emilio Segre, Stanislaw Ulam, Edward Teller, I. I. Rabi, Hans Bethe, and John von Neumann—agreed to join Oppenheimer in his new central laboratory.

Groves required a remote site for the location, west of the Mississippi and far from established population centers. He preferred a spot accessible by road yet situated in a natural bowl so it could be fenced and guarded. Several sites in the Southwest were selected but they either did not meet the criteria entirely or were not acceptable to Oppenheimer. Oppenheimer then suggested the Los Alamos Ranch School for Boys, which he knew about from previous vacations in New Mexico.

The Ranch School was located in the upper Rio Grande Valley on the Pajarito Plateau west of the river and at the bottom of the Jemez mountains. The Pajarito Plateau had always been marginal land. During Spanish colonization it acted as a buffer between hostile nomadic groups like the Apache and Ute and more established Spanish settlements. In 1742, the viceroy of Spain granted the least rugged area of the Plateau to Pedro Sanchez. The Sanchez family sold the grant to Ramon Vigil in 1851. The land was too remote to attract the railroad during the nineteenth century when developers purchased many isolated and distant tracts of land in the country. Only a few rugged individuals eked out a subsistence living on the Plateau homesteading.

The grant changed hands many times over the years until in 1917 it was purchased by Ashley Pond and four Detroit businessmen as an investment. Pond and his partners tried unsuccessfully to establish a resort on the Ranch. When that failed, his partners sold off their part of the investment leaving Pond with the Ranch. He turned his hand to education. By 1943, when the school came to the attention of the Manhattan Project it had been in operation for 26 years. The school taught the children of elite East Coast families a rigorous curriculum mixed with a daily outdoor regime.

The government quickly appropriated the school and twenty-six other properties from local inhabitants. Combined with already government-owned land, the Hill, as Los Alamos came to be called, eventually comprised some 9,000 acres. The M. M. Sundt Construction Company and the architectural firm of New Mexico state archictect W.C. Kruger began immediately to transform the rustic boy’s school into a military base.

Sundt and Kruger modified and expanded the ranch, which originally consisted of fifty-four buildings. Initially they added thirteen buildings to the main work or Technical Area and 334 apartments for housing scientists, staff, and their families. The Sundt/Kruger apartments, after the headmaster’s quarters of the Boys Ranch, were the most desirable living arrangements in the hastily erected secret city. These two- and three-bedroom efficiencies had hardwood floors and fireplaces. Later construction contracts provided pre-fabricated houses which lacked even these modest architectural features and resembled temporary military housing. Los Alamos increasingly housed people in Quonset huts, Pacific hutments, and expandable trailers as the population burgeoned from several hundred to over 6000 residents by war’s end. The Hill became a double-walled city—the residential area sported a chain link fence topped with barbed wire and another internal fence separated wives and children from the area where research and development occurred.

Los Alamos attracted not only émigré scientists from Europe but U.S. chemists, physicist, engineers, and even promising graduate students. Los Alamos also initially hired 160 women--25 scientists, 50 lab technicians, 15 nurses, and 70 filing clerks/or secretaries. Local civilians sought positions building, provisioning, and servicing the new city. Priority often went to men and women who lived in the surrounding towns and pueblos so as not to add to the already crowded city. A sizeable military staff also began arriving in Los Alamos, comprised of the Provisional Engineering Division, Special Engineering Division, Military police, and Women’s Auxiliary Corps.

A shroud of secrecy surrounded life on the Hill. Officially Los Alamos didn’t exist except as the nondescript P.O. Box number 1663. General Groves referred to the facility in code as Site Y and people reached it by going through Dorothy McKibben, manager of the Manhattan Project office in Santa Fe. New recruits arrived at 109 East Palace Avenue and McKibben put them on a bus which shuttled them to Site Y. At first residents could not travel any farther than a 100 mile radius--no farther than Albuquerque, Santa Fe, Lamy, Cuba, or Las Vegas. However, eventually Oppenheimer lifted travel restrictions to anywhere within the continental U.S. Secrecy did not stop at the fences but extended into the family home. Wives and children knew nothing about their husbands' or fathers' work, and many discovered the true nature of the work only after the atomic bomb devastated Hiroshima and Nagasaki.

Emilio Segre, Oppenheimer’s protégé, greeted new scientists and technicians upon their arrival and briefed them on the main MED mission—to build an atomic bomb. Oppenheimer quickly asked all scientists to call the bomb a “gadget” to avoid any secret information from trickling down to staff and service personnel.

Early efforts to create a gadget at Los Alamos centered on a gun-type plutonium weapon. This approach came out of discussions between Manhattan Project scientists at a conference held at Berkeley in 1942, before the laboratory at Los Alamos was operational. The gun-type weapon, code named Thin Man, used a barrel to shoot or collide two pieces of fissile material together, causing an explosion. Oppenheimer created four divisions at Los Alamos to carry out this work— Theoretical, Experimental Physics, Chemistry-Metallurgy, and Ordinance Engineering.

In 1944, Segré discovered that using plutonium for Thin Man was impossible, as it would pre-detonate. Oppenheimer then reorganized his divisions and ordered researchers to focus on an implosion type weapon. An implosion device, code named Fat Man, compressed shaped conventional explosives around a fissile core, to cause an atomic explosion. Work continued on a gun-type weapon, using uranium instead of plutonium. This weapon was re-named Little Boy.

On 16 July 1945, a prototype of the Fat Man weapon successfully exploded at Trinity Site in the New Mexico desert. The next month the U.S. Army dropped both Fat Man and Little Boy over the Japanese cities of Hiroshima and Nagasaki killing over 200,000 people. Japan surrendered unconditionally 14 August 1945 ending WWII.

In the aftermath of the war, Congress waffled about the status of Los Alamos. Groves maintained that keeping a “nucleus of staff” at Los Alamos was critical to national security and the future development of nuclear weapons. Nevertheless, most scientists and their families left the Hill en masse, glad to abandon the cramped and sub-standard living conditions now that they had completed the war-time mission of the MED. Many returned to their previous occupations. Even Oppenheimer joined the first wave of parting scientists to accept an academic position at Cal Tech.

Norris Bradbury replaced Oppenheimer as director of the laboratory. Bradbury had directed the testing of the gadget at Trinity. Bradbury acknowledged a duty to continue the work begun at Los Alamos during the war. He commented, “I feel that the bear which we have caught by the tail is so formidable that there is a strong obligation upon us to find out how to let go or hang on.” In December of 1945, the Army and Navy announced plans to field test atomic weapons. Operation Crossroads, as the Marshall Island tests were code-named, gave Los Alamos a renewed purpose and mission.

The army then attempted to stop the exodus of scientists and technicians from the Hill by making the town a more desirable place to live. On 29 July 1946 the army awarded the McKee Company a contract to build a suburb west of the town site consisting of 300 single-family homes. Although modest two- to three-bedroom homes made of cinder block or wood frame, they were a huge improvement over war-time accommodations. Groves also approved a community center which included such amenities as stores, a recreation hall, movie theater, and bowling alley.

World events, however, not amenities transformed Los Alamos from a temporary army installation to a thriving town of over 12,000. After WWII, the United States’ uneasy alliance with the Soviet Union grew more and more tense. The U.S. and Soviet Russia (U.S.S.R.) began a forty-year ideological struggle that historians have identified as the Cold War. The Cold War conflict centered on competing economic and political philosophies (democratic vs communist) and attempts to persuade the countries of Europe, Asia, and the Middle East to ally with one side or the other.

As relations between the two sides became more tense, each country used atomic weapons as a strategic threat in the conflict. The Soviets had also developed an atomic research program during the war and both countries engaged in espionage to advance their research. In 1949, the Soviets detonated their first atomic weapon ahead of all state department predictions. A shaken U.S. accelerated its program to develop hydrogen or thermonuclear weapons. The thermonuclear weapon unlike the atomic bomb had no limits on its destructive potential. In 1952, when the U.S. successfully exploded its first thermonuclear weapon at the Bikini Atoll, it exceeded all expectations completely dissolving Elugelap one of the Marshall Islands. The device, code-named Mike, detonated with a yield of 10.4 megatons—ten times more powerful than the bombs that devastated Hiroshima and Nagasaki.

The development and refinement of thermonuclear weapons brought thousands of new workers to Los Alamos. The first atomic and thermonuclear devices were large and cumbersome. Weapon designers at Los Alamos worked to improve nuclear weapons making them lighter, smaller, and more powerful. As the Cold War continued the U.S. and the U.S.S.R. competed to produce more and better nuclear weapons creating huge arsenals of thousands of weapons each. By 1960, the U.S. stockpile had over 18,000 weapons in it—largely due to research and design efforts of the weaponeers at Los Alamos. As the Cold War waned, particularly in the 1970s, Los Alamos, like other national laboratories, began to increase its other scientific research programs. In addition to weapon design, Los Alamos pursued research in the fields of nuclear energy, radiation effects, fusion, computers, new materials, accelerators, and other physics, health, and environmental projects.

In 1992, international treaties banned all testing of nuclear weapons and the U.S. stopped new weapon design. Los Alamos began to engage in stockpile stewardship---the maintenance of the U.S. nuclear weapons stockpile through advanced computing methodology.


Sources Used:

Groves, Leslie R. Now It Can Be Told: The Story of the Manhattan Project. New York: Harper and Row, 1962.

Hoddeson, Lillian, Paul Henriksen, Roger A. Meade, and Catherine Westfall. Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years, 1943-1945. Cambridge: Cambridge University Press, 1993.

Hunner, Jon. Inventing Los Alamos: The Growth of an Atomic Community. Norman, Oklahoma: University of Oklahoma Press, 2004.

Loeber, Charles R. Building the Bombs: A History of the Nuclear Weapons Complex. Albuquerque, New Mexico: Sandia National Laboratories, 2002.

Rhodes, Richard. The Making of the Atomic Bomb. New York: Simon and Schuster, 1986.

______. Dark Sun: The Making of the Hydrogen Bomb. New York: Simon and Schuster, 1995.

Rothman, Hal. On Rims and Ridges: The Los Alamos Area Since 1880. Lincoln: The University of Nebraska Press, 1992.

Szasz, Ference Morton. The Day the Sun Rose Twice: The Story of the Trinity Site Nuclear Explosion July 16, 1943. Albuquerque: University of New Mexico Press, 1984.

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