No. of Particles I Station ! 250.04 32 | 250,27 250,24 Averare Investige ted Density | Standard Ueviation a ed TABLE §.5 - Particle Density 222k F942 29 2.40 | 1@ 2.45 7h 5.5 GROSS FEYSICAL CYARACTERICTICS OF FALLOUT Comprehensive date on ohysical and chemical characteristics of fallout are presented in the Project 2.6a renort.28 551 Surface Lard Shots It is well established that the fallou' from the island shots was very simiiar to that which occurred after Mike shot et IVY, namely dry, white, opaque, irrempularly shaped particles. Figure 5.10 shows Shot, 1 fallout as it arrived on the purmed paper collector loceted at station 250.04. It ie tynical of fallout from Islerd detonations in the Pacifie Proving Groum?, 52562 Surface Water Shots Positive evidence of particulate fallout wag found in the differential collector iucated at Alice Island after Shot 6. However, the furmed paper collecters located on the free floating buoys after Shot 2 showed no eviderce of ary particles visitle to the naked eye. It is felt ty come olservers that the fallout tvom the surface weter detons- tions was primarily in the form of 4 mist or aerosol, This is substantiated to some degree vy the observetion of the identificetion flags located on the sea stations after Shot 2, These flags were hivhly radioactive, many times more active than the total collectors of the same station. It is reasonatle to asswn- that a moist fine fallout would te absorted by the flapping flags much more easily than would a dry particulate, 5.6 TINE OF ARRIVAL OF FALLCUT The primary instmment for determinine the period over which feli-~ out took plece was the differential fallcut collector. Information on time of arrival wes also obtained from the ganrs time-intensity recorder stationed on How Islend; further information may te obtained from timeintensity recorcers onerated by Project 2.2. Also, limited evidence of arrival tire is uvailabLle from ‘he Task Force Ship's logs and Project 6.4. 67 SN ems ‘ ww A 4s { Ln SToisboes | , . |eo, Ag/ew em) i (ver cent)