Early sampling of ‘Orange shot did not sees feasible, since the debris clad was expected to be fairly dense, and because of rocket liaitations sa pling at burst altirude would have been difficult at the planned range. was decided to sample the cloud 35,000 feet above che burst point. It Sanpler rockets were to pass through this elevation above the burst at £0, 6&0, 90, and l@) secoods after burst tine. 5-1.2 Debris Characteristics at 250,000 Feet : Betore exploring sampler designs, certain aspects resulting from the detonation of the dewice should be examined. Of particular interest are de- bris clood disseter, clond rise, and particle size. In cousidering these effects in conjunction with sampler design, calculation results are suumrized. SC-h172(TZ) gives a more complete analysis.! Ambient conditions at warious altitudes were considered. By this is meant the walues of pressure, density, and temperature assigned to the warious eievatioas. Cloud Diameter. Seweral authors have already considered burst effects at the 250, 000- foot elevacion.“3 Their treatments of the possible diameter achiewed by debris from the burst are incowplete, since they consider debris bebswior only until it has mixed with a wess of air equal to that of the bomb itself. This corresponds to radius of about 1000 feet fram the burst point at 250,000 feet. Their treateents overlook the momentum associated vith device expansion. Ir is trve that the kinetic energy which the expansion represents is rapidly dissipaced as the material contacts the surrounding air. ever, is conserved. The mowentuz, hov- A study of the consequences of this momentum conserva- tion is carried out in the above-mentioned report by the author, The result fs a prediction of a spherical lgyer (teraed "shell"} of material expanding from the burst point. This shell is made up of the bowb debris and the air which was originally between the ‘shell surface aod the burst point. Analytic expressions may be written for this shell velocity, for the time required to achieve a particular radics, and for the kinetic energy remaining in the directed motion of the shell particles. These are:

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