And if the water is uniformly contaminated to the depth Z centimeters, the total amount lp of activity In the water column per square centimeters, is . Ip = Zem Iz = 16.5 Zom $4 = Mev/cm?/sec This can be imagined to correspond to the fallout density on a smooth, fixed plane, at timet. If the fallout has several constituents, the fallout density can be expressed Ip = >> njEj i And if P; = the fraction of energy in the ith component mE; = Pyle so that the dose at elevation X due to the ith constituent is, sEsha /E; —-s nd; = ae | nll ds By; (jc Xx) = Mev/cem?/sec 8 “ux and the total dose in air is, Sa [ A! fae a or niEjha(E;) 4 4 eo e* “px or by substitution, the total dose at elevation X is, in Mev/em*/sec, ha ©) e® ea [ax ve8 t “ux or, . wo . -8 16.5 Z¢ >» PihaEi) / ode By (ue x) 7 2 8 “px Therefore a dosimeter at elevation X above the hypothetical plane would read, at time t, and in milliroentgens per hour, 6 = 1.45 x 1075 (1000) (3600) > njd; = 52 y nye; Ps = (52) (16.5)Z¢4 D> Pyha (Ep f e8 ds B; (te x) i “px 89