f, Radiochemical analyses completcd on samples from DOG shot indicate that the fissiong yicld curve roughly approximates that of thermal-neutron fission, with a ratio of fission yields at the curve maxima and minima of about 200, g, Decay rate measurements have been made on three samples of the cloud fron cach of the three shots, These samples were taken at maximum, medium, and minimum altitude of cach shot and included both efficient and inefficient collections. Pre- sent data indicate a difference in the shape of the decay curves between officient an inefficient collections, 3. THERMAL EFFECTS ON MATERIALS a, The objectives of this part of the program were to obtain d-ta on the effects of thermal radiation on materials, which would provide an adequate base for the future conduct of a laboratory program, and to determine the degree of correlation between the thermal-radiation cffects of an atom bomb and the cffects of sources presently being used in laboratory studies. This part of the program participated in HASY shot only. b. Results showed that the stations were well~sclocted as to Location and were well-designed and well-instrumentcd for the execution of the project, Results to date indicate that the duration of cxposure and the total radiation received at various stations were lower than had been calculated, The total cnergy received at the far stations was greater than that received at the close stations probably because of obscuration by dust of the lower part of the fircball. Both the peak in- tensitics and the effects on materials, however, decreased succ-ssively from the clos to the far stations, The maximum intensity was observed at about 1/3 to 1/2 second after the detonation, e, It is tentatively concluded that material damazo is closely desendent on both the total energy and its rate of delivery: that for practical purposcs therefore the total energy delivered cannot be usud alone as a criterion of damage. ad. served, No significant amount of damage duc to ultraviolet radiation was ob+ For practical purposes, the total damage can be attributed to radiation in the visible and infra-red regions of the spectrum, The data have not been studicd to a degree to permit diffcrontiation between relative effcets in these spectral reglons, 4. EXPOSURE OF COMBAT VEHICLES a. The objective of this part of the program was to determine the tacti- cal effoctiveness of atomic weapons when employed against concentrations of armored x