although there is little possidosimeters can be made adequate with minor changes, intensity ranges. bility that any one type can be made adequate for all No particu- gh several cun be correct lar type of survey meter was entircly satisfactory, althou ed by the elimination of minor flaws, Telemetering crater survey units dropped by necessary. aircraft performed fairly satisfactorily, although some modifications are Airborne radiac equipment performed adequately. For 4 more detedled discussion of Program 5.0, see Appendix "E", 12. PROGRAM 6.0 — PHYSICAL THOTS AND MSASURMMENTS The objectives of this program were to deturmine many physical cffects and characteristics of atomic bomb detonations, These included: particle sine end dis- es, falltribution studies, thermal effects on miterials, cxposure of combat vehicl out distribution, interpretation of survey metcr data, evaluation of filter maber jals, contamination and decontamination studies, radiation field of the atomic cloud: evaluation of protective clothing and collective protector equipment, Instrumenta- : ge » BS iti tion, in general, operated very well, | The maximun thermal effect was observed from one-third to one-half second after detonation; dust greatly reduced thermal radiation, especially at close stations. Practically all thermal radiation damage occurs in the visible and infrared regions of the spectrum, ‘The experiments with M26 and M-1.6 tanks showed that, for a 50 Kkiloton, 300 foot tower detonation, both radiation and blast effects would cause a vory high percentage of deaths among the crews within 1000 yards, - Depot maintenance would be required on vehicles within 750 yards; beyond 1200 yards no damage would be incurred. The study of fall-out showed that over 90% of the total activity of the samples collected was contained in the greater than 20 micron fraction. Individual particles wore mostly black spheres, either alone or attached to sand grains. The interpretation of survey meter data is contimiing; no definite results are available now, Preliminary results on filter matorials indicate that filter efficiency of the materials tested approximates that determined in the laboratory. In the contamination-decontamination studies 1% was determined that cleaning methods must be carefully selected on the basis of both the material and the type of contaminant. In studying the cloud radiation field it was found possible to accurately define the cloud boundaries, and that the greatest radioactivity occurred where the greatest particle density occurred. The study of protective clothing showed that ordinary laundry facilities are entirely successful in removing radioactive contamination. Collective protector equipment appeared-to bo ee Peieaaiaea te Ee TS Gerla eS eatrag eypee ATU CRESS ‘t ART ~~ Jeo