value waa obtained from a total collector sample and must be corrected for collector efficiency which at this dose rate was 43 per cent (see Fig. 4.1). Therefore, the experimentally determined bomb fraction per square foot for 4 gamma field of 1 r/hr at 9 days equals s -13 713 = 3.45 x 10° ,/sq ft = 3.7 x 107)5/sq om, : 0 Bs Since 1 r/hr ak9 days is produced by 1.03 x 10° photons/sec/sq cm and Y, = 1.47 x 10** photons/sec/sq cm the calculated fraction of the device at this station is a4 1,03 x 10° 1.47 x 10 37 7.0 x 10716/sq cn, U7