. . . . « oo. . . + 4 eee eee « * . 4 . ay . . wnene aaee soeee sbeee ‘ . . field test,* using @ phantom man extosed to both ‘he’ initial and r esidual radiation, The depth doses for cach Situation are shown in ig. 1.5, with all data as per cent of the 3 centimeter dose. With the diver:dny initial radiation from the point of explosion, the exit dose was seen to be 63 per cent of fhe 3 cm dose, but with the diffuse residual feld of fission product radie- tion, a surface duse some eight times greater than the 3 ¢m and deeper dose from the harder gamma components was observed. This is seen to be of the same order of magnitude as that estimated above, At heichts above and below the 3 foot level this surface dose would become Jower and higher respectively, but prubably would not exceed 50 times the 3 foot ir samma dose or &0 times the midline dose, even in contact with the ground. An estimate of skin duse t due to ground contaimination for the Rongelap case would result, for exarnple, ina fisure of t aboul 2000 rep to the dorsum of the foot, 600 rep at the hip level, and 300 rep at the head if continueus exposure with no shielding occurred. Some reduction in dose undoubtedly resulted from shielding and movement, and it seems probable that the external beta dose from local | skin contamination far outweighed that (rom the ground in importance, This is emphasized by Oana 3b ie Wu Le eeanv gpo SSdT DATE oop/'¥ STATUS VERIFIED UNCLASSIFIED the fact that clothing probably reduced the beta dose from the ground by 10 to 20 per cent. *F. W. Chambers, Project 2.2b, Residual Garama Depth Dose Measurements in Unit- Density Material, AFSWP, WT-719, Operation UPSHOT-KNOTHOLE. - 23 at OS TE meet TT ere, ee Tn wom, wea ey epeepe parmage I OEY ol RTS TR FONTS AOA TLR tok pt Peeeb a aTE ST TSAR RR eete ae re ee 8