Appendix C COMPUTATION OF DOSE AT THREE FEET ELEVATION C.1 COMPUTATION OF DOSE AT THREE FEET ELEVATION FROM MEASUREMENTS OF DOSE IN WATER Wherever possible, the notations of AFSWP 502 will be used. Let $4 be the submerged instrument’s reading converted to mr/hr after corrections by use of calibration curves which take into account all corrections for: (1) radiation coming from all angles, (2) mixed radiation having the assumed fallout spectrum of energy, and (3) contamination of instrument in the water. Then; ; j=i ot = 1.45 x 10-5 x 1000 x 3600 5) ba (Ey) f (Ey) = mr/hr j=e Where: there are several constituent fluxes, J(Ej) each having photon energy Ej and the dose rate given by the sameflux to the water will be: : Di= D hy (Ej) F(Ej) = Mev/cm*/sec, j Where: ha (Ej) is the true absorption coefficient in air, and hy (Ej) is the true absorption coefficient in water. But these coefficients are proportional to the number of electrons per cubic centimeter, or numerically (Lauritsen AFRRT, Vol. XXX No. 3, September 1933) from: hw (Ej) _ 860 ha (Ej) 1 which is approximately independent of energy. So that: 860 De = 1.45 x 1075 x 1000 x 3600 = 16.5 o when ¢4 is in mr/hr, and D, is in Mev/em*/sec. But, if sources are distributed uniformly throughout a very large, homogeneous, scattering and absorbing volume, considerations of conservation of energy require that the specific rate of emission of energy is equal to the specific rate of absorption in the medium. So that the emission rate is, at time t and at depth Z, Iz = Dt Therefore: Iz, = 16.5 ¢ = Mev/cm*/seo 88