2. Shot Quince, detonated on the ground, produced an alpha~hazard area (1,000 ug/sq m), before translocation, of no more than 100-yd radius from ground zero. 3. Shot Hamilton, detonated on a 50-ft tower, produced a dpazardous alpha-~contamination area within a 10-yd radius of the tower. + : 4, The alpha-contamination pattern can be significantly changed ‘by translocation of contaminated particles by the wind. 5. More experimental evidence is mecessary to confirm the validity of the jet theory. CWLR - 2394 - SIGNIFICANCE oF THERMAL RADIATION AS A HAZARD TO TROOPS IN FOXHOLES (U). J. J. Mahoney, J. C. Maloney and D. T. Kilminster, May 1960. CONFIDENTIAL (u) Personnel in open foxholes are partly protected against the hazards of blast, neutron and gamma radietions, and thermal radiation from. nuclear detonations. A study was made of the current theoretical and experimental data to determine the slant distances at which immediate casualties to troops may be expected because of these hazards. A series of curves is published in Capabilities of Atomic Weapons (U), Technical Manual 23-200, showing the distances for a 50 per cent probability of immediate casualties attributable to the above injury-producing effects to troops in the open field. The series of curves was used as a basis for determining the probability of immediate casualties to troops in standard 2 by 4 by 6-ft open foxholes. ¢ The most extensive measurements to date of thermal radiation in oxholes were done at Operation UPSHOT-KNOTHOLE. It was suspected that the thermal-measurement data were unreliable because of the thermal detectors used and certain assumptions made for the calculations. For ' purposes of rechecking some of these thermal data, the present work was undertaken by using thermal radiation from sunlight instead of that from & muclear borb. These solar-radiation measurements indicated that the thermal flux in the shaded portions of open foxholes is a significantly greater fraction of the total thermal flux than is indicated by the data obtained at muclear tests. : ep The following conclusions were reached as a result of this work: = 1. When the thermal radiation is incident side-on (6-ft side), RESTR ATOM GY TA WNRG — 68 uy _ the thermal flux is equal to 10 to 25 per cent of the above-ground value ”