RELATIVE IONIZATION RATE TIME (O4YS) Figure 3.14 Gamma ionization decay as a function of relative ionization rate, Shot 4. Using an estimate of the beta-to-gamma ratio and the average gamma energy, the gammarate contours were also related to the device fraction. The Shot 1 contour data, when reduced according to an assumed fission yield of beta-to-gamma ratio of 0.45, and an average photon energy of 0.344 Mev at D + 8 days, accounted for 57 percent of the activity of the shot. Another calculation that normalizes the data using the Mo™ device fraction and the measured gamma field at the Site How station accounted for approximately 30 percent of the activity in the pattern. For Shots 5 and 6, the beta counts of the water samples were used to normalize the contours constructed from the surface and aerial surveys. These calculations accounted for only 10 percent and 8.5 percent of the activity of Shots § and 6, respectively, in the 56