SECTION 12 TEST OPERATIONS It is not intended to discuss in this report the details of the experiments conducted or their results. However, it is believed worthwhile to review the basic objectives of the tests and to outline the scope of experiments conducted. Since the close of the war the Atomic Energy Commission’s Los Alamos Scientific Laboratory has been carrying out a number of complicated calculations and an extensive program of experimentation in an attempt to design new and improved weapons. It was believed that better weapon designs than those of Hiroshima and Nagasaki were available, but it was not certain how much better these new designs were. One of the principal objectives of the Sandstone tests was a measurement of the efficiency and yield from these new designs. The achievement of this objective required a primary program of experiments. A secondary program of experiments resulted from a desire of the Services to take advantage of these tests by exploring problems of particular concern to the Armed Forces. Individual experiments were conducted by groups from the Los Alamos Laboratory or by groups from outside agencies under contract to the Los Alamos Laboratory. Contract groups were used to avoid withdrawing talents from the Laboratory to such an extent that the major programs of the Laboratory would suffer. Liaison between the Scientific Director and the contract groups was effected by Los ~mos liaison personnel. The experiment of highest priority was the radiochemical work done under the leadership of Dr. Roderick Spence at Los Alamos with Dr. Melvin G. Bowman responsible for operations at Eniwetok. T’he drone aircraft of the 1st Experimental Guided Missiles Group obtained air samples for this work. Drone tanks were used for collection of ground samples. All analysis was done at Los Alamos Laboratory, samples being rushed back by C-54 aircraft after each shot. A second experiment was to measure the number and the energy of neutrons as a function of distance. This group, drawn from Los AIamos, was under the direction of Mr. G. A. Linenberger, assisted by Dr. William Ogle. Experiments measuring the spectrum of gamma radiation were done under the direc- ~ tion of Dr. Francis Shonka by a group from the AEC’S Argonne National Laboratory. Dr. L. D. P. King was the Los Alamos Laboratory liaison man with this group. The consulting engineering &m of Edgerton, Germeshausen and Grier, of Boston provided another contract group. This group was responsible for the complicated timing signal and remote control tiring circuits which were necessary in order to fire the bomb and to switch on all of the self recording experimental equipment at the right instant with respect to the time of detonation. This same group also made measurements of the rate of growth of the nuclear reaction in its early stages. Dr. H. E. Grier assisted by Dr. H. E. Edgerton was in charge of this group. Earlier in the planning phases of Sandstone this Moup supervised the design engineering of special shelters and other instrumentation installations. The blast measurement group was dfawn from the Naval Ordnance Laboratory, Aberdeen Proving Ground, and the David Taylor Model Basin. Dr. G. K. Hartmann of the Naval 127