ee, good definition both of the fallout front and of the total falleut was obtained. with the exception of the probe andj monitor mounte? on the boom of the YAG-40 all instruments aboard the three project ships were operated during the fallout period. The YAG-40 occupied a position close to the estabilished line of maximum fallout ani received a large quantity of fallout material (TOA = H # 34, approximately); peak observed intensity on the deck, however, was only about 9r/hr (H £ 7). Samples were obtained by the Special Incremental Collector until well heyond peak activity and all laboratory studies planned for early times (activity measurements, physical observations, decays ani gamma spectra) were performed; these data are currently being reduced and will be reported when available. It is clear, however, that they vill suffice for a compsraiively detatled characterization of the fallout at this lccaticn. The YAG-39 also occupied a position on the established line of maximum fellout, but for reasons not clearly under-~ stood, received only a relatively light fallout (TOA =H # 124, approx- imately); the intensity on the deck did not exceed 40 mr/hr (HK # 26), The readings of all instruments were consistent, however, and good de~ Finition of the fallout at that point was obtained. It was, for example, obeerved that after the first peak was reached, normal decay did not occur; instead the activity built up to a second peak, then began to decay, indicating a second arrival of primary fallout. It was later es- tablished that the wind structure had collapsed during this period, and it is belicved thet the data ottaine? on this vessel may enable an eventUal analysis of the behavicr of fallout under such conditions. Due to the collapse of the winds pricr to the expected time of arrival of fall-

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