Document Details


Title:
OPERATION TEAPOT, NEVADA TEST SITE, FEBRUARY - MAY 1955, PROJECT 2.3B, GAMMA RADIATION FIELD ABOVE FALLOUT CONTAMINATED GROUND
Subject Terms:
TEAPOT OPERATION
Document Location:
Location - DOE/NNSA NUCLEAR TESTING ARCHIVE Address - P.O. Box 98521 City - Las Vegas State - NV Zip - 89193-8521 Phone - (702)794-5106 Fax - (702)862-4240 Email - NTA@NV.DOE.GOV
Document Type:
REPORT
Publication Date:
1955 Feb 28
Declassification Status:
Unknown
Document Pages:
0098
Accession Number:
NV0006228
Document Number(s):
WT1225
OpenNet Entry Date:
1994 Aug 26
OpenNet Modified Date:
2003 Sep 18
Description/Abstract:
ONE OF THE OBJECTIVES OF PROJECT 2.3, OPERATION TEAPOT, WAS TO FIND TH E RELATIONSHIP BETWEEN FALLOUT GAMMA-RADIATION-SOURCE SPECTRA (WHICH C AN BE MEASURED IN THE LABORATORY) AND THE PHYSICAL CHARACTERISTICS OF THE RADIATION FIELD EXISTING OVER A UNIFORMLY CONTAMINATED AREA. THIS OBJECTIVE WAS MET BY MEASURING THE ENERGY AND DIRECTION DISTRIBUTION OF GAMMA PHOTONS 3 1/2 FEET ABOVE A FALLOUT-CONTAMINATED AREA NINE DAY S AFTER THE BURST OF A FISSION DEVICE USING A MOBILE-SCINTILLATION SPE CTROMETER. THE COMPLETE INTERPRETATION OF THESE MEASUREMENTS YIELDED THE NECESSARY RELATIONSHIPS. A SIX-WHEEL-DRIVE MILITARY TRUCK (FIGURE 3.1) WAS EQUIPPED WITH A SHIELDED AND COLLIMATED 4-INCH-BY-4-INCH DIA METER SODIUM-IODIDE-SCINTILLATION DETECTOR WHICH COULD BE AIMED IN ANY DIRECTION (FIGURE 3.2). A TWENTY-CHANNEL PULSE-HEIGHT ANALYZER INSID E THE TRUCK (FIGURE 3.3) RECORDED THE PULSE-HEIGHT DISTRIBUTION FROM T HE DETECTOR. THIS INFORMATION WAS THEN CONVERTED TO A GAMMA-RAY ENERG Y SPECTRUM. BY MEASURING THE INTENSITY AND SPECTRUM OF THE RADIATION AT SELECTED DIRECTIONS THE COMPLETE ENERGY AND DIRECTIONAL CHARACTERIS TICS OF THE RADIATION COULD BE INTERPOLATED (FIGURES 5.1 THROUGH 5.12) . THE DIRECT, UNSCATTERED, RADIATION WAS READILY RECOGNIZED FROM ITS UNIQUE DIRECTIONAL DISTRIBUTION DERIVED ON THE BASIS OF SIMPLE THEORY (APPENDIX A). THREE PARAMETERS ENTERED: THE SOURCE ENERGY, SOURCE STR ENGTH, AND THE THICKNESS OF OVERLYING INERT MATERIAL. THESE PARAMETER S WERE EVALUATED AND SHOWN TO BE CONSISTENT WITH OTHER MEASUREMENTS (F IGURES 6.3, 6.4, AND 6.6). THE INCONSISTENCIES WERE SHOWN TO BE OF TH E TYPE AND MAGNITUDE EXPECTED ON THE BASIS OF OTHER EXPERIMENTAL KNOWL EDGE ABOUT FALLOUT (APPENDIXES C AND I). THE EXCESS RADIATION OVER TH E DIRECT RADIATION WAS ASSUMED TO BE CAUSED BY SCATTERED RADIATION. I TS CHARACTERISTICS APPEARED TO BE PROPER FOR SUCH RADIATION (FIGURES 6 .1, 6.2, AND APPENDIX B). THEORETICAL COMPUTATIONS WERE NEEDED FOR DE TAILED COMPARISON. THE RESULTS WERE EXPRESSED ALSO IN TERMS OF THE EN ERGY AND DIRECTIONAL DISTRIBUTION OF BIOLOGICAL HAZARD (FIGURES 6.7 AN D 6.8). THE TOTAL HAZARD WAS COMPUTED FOR COMPARISON WITH A RADIAC ME ASUREMENT MADE IN THE FIELD. IT WAS CONCLUDED THAT THE DIRECT, UNSCAT TERED RADIATION FIELD, WHICH CONTRIBUTES ABOUT 80 PERCENT OF THE ROENT GEN EFFECTIVENESS, COULD BE COMPUTED FROM THE SOURCE STRENGTH AND SPEC TRUM ON THE BASIS OF SIMPLE THEORY REQUIRING KNOWLEDGE ONLY OF THE THI CKNESS OF OVERLYING INERT MATERIAL. FURTHER EXPERIMENTS ARE NEEDED TO ESTABLISH THE CHARACTER OF THIS OVERLYING MATERIAL AND THE VARIATION OF ITS THICKNESS WITH TIME AND OTHER PARAMETERS. FURTHER EXPERIMENTS ARE NEEDED TO ESTABLISH THE MAGNITUDE AND CAUSES OF VARIATIONS IN THE FALLOUT SOURCE STRENGTH AND SPECTRUM. THE CONCLUSION WAS REACHED THAT THE SCATTERED RADIATION FIELD WAS OF THE SORT TO BE EXPECTED. COMPUT ATIONS OF THIS FIELD ARE DIFFICULT, BUT DEFINITIVE COMPARISONS WITH TH E EXPERIMENTAL RESULTS MUST AWAIT THEM.


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