v Project 2.63 - Collection end Characterization of Fallout with Time T. Triffet OBJECTIVES To collect samples of fallout and measure radiation field intensities with time at various distances from high yield lend, water and air thermonuclear detonations. To study these samples from early times with respect to gemma end beta activity, to analyze them for chemical and radiochemical composition and to determine certain of their physical properties, including distributions of particle sizes. ¥ DESCEKIPTICN AND EXPERIMENTAL PROCEDURES Two YFNB barges and three pontoon rafts were anchored in Bikini Lagoon. YFNB-29 carried two standard platforms with major arrays of instruments and YFNB-13 carried one. Each major array consisted of four open-close total collectors, two always-open total collectors, one incremental collector, one gamma intensity vs time recorder, and one wind speed and direction recorder. The arrays on the barges were fully automatic. Each pontoon raft carried an always-open total collector, a time of arrival detector and a film pack to measure total dose. An array of 16 skiffs was deep~sea anchored by Project 2.62 between 10 and 30 miles from ground zero in the expected fallout ares. Each carried a minor arraye YAG-39 was located approximately 25 miles, YAG-4O approximately 40 miles and LST-611 approximately 60 miles from ground zero; all, however, were at different azimuth angles. Each wes extensively instrumented with a major array supplemented by incremental collectors and high volume filter units. COPIED BOE LANL &C | - 16 -

Select target paragraph3