1. JULY 1947 TO JULY 1950 The newly-created Atomic Energy Commission took over responsibility for the atomic energy program on January 1, 1947. On July 2 the Office of Santa Fe Directed Operations (nowSanta Fe Operations Office) was established to administer the atomic weapons field program. Two weeks later, the present Manager of SFOO arrived at Los Alamos to be the first civilian manager of the project. In mid-1947, Los AlamosScientific Laboratory, assisted by a small Sandia Branch, was carrying the major weight of weapons manufacture. There was some production of mechanical components at the Army's Rock Island (Ill.) Arsenal. The Salt Wells Pilot Plant of Naval Ordnance Test Station, Inyokern, California, was producing high explosives. There was little participation by private industry. Two weapons types were being produced in extremely limited quantity. Units going into stockpile were laboratory-fabricated. The limited production chain had only one source for each major com- ponent. Three major modifications of one Mark weapon were in early development. The SFOO assignment at the beginning of its operations represented a tremendous undertaking. It was required to build the mandatory physical plant and organization, while at the same time assuring continuous production of weapons, and maintaining basic and applied research for development of more powerful, more varied, or more efficient weapons, The scope and priority of initial assignment were direct reflections of the situation: To build and develop at Los Alamos, the heart of the program, a com- munity that would be adequate to obtain and to retain the type of personnel required. This meant rebuilding and expanding the community. To provide a climate in which LASL could proceed with its job of basic nuclear research and development, and to provide a Technical Area physical plant adequate for the job. To organize and supervise an ordnance development, production, and testing complex, relieving LASL of these responsibilities. To expand production and facilities at other sites, in order to achieve a continuous flow of component parts. To evolve an organization competent to achieve basic management and program objectives. ALGO Approximately two and one-half peacetime years provided a relatively secure period unhampered by wartime expediencies, during which programs could be adequately planned and activated. The value of time for orderly development of a basic SFO struc- ture was underwritten by national and international events near the end of the period. In the Autumn of 1949 Russia tested an atomic weapon, and SFO moved immediately out of its "peace-time" period into one of increased mission urgency and of "crash" programs. This was intensified in early 1950 with the decision to go all out on thermonuclear weapon development. It was further intensified three days before the end of the reporting period by the outbreak of the Korean War. DORAN