0021620 Eee, G.(t) = pplt) ipp(t) + Dorjest,(t) (21) As’ a generalized point function, Eq. 21 would have G,(t,x), r4(x), and Fpp(x,t) with the latter two given as explicit functions of the distance. The effect of terrain and instrument response to radiations gener- ally will tend to give lower values of igp(t) and i,(t) than those calculated for an infinite smooth plane surface. These factors will also influence the value of G,(t) to give larger observed values of the con- tour ratio. : As with fractionation, these factors would be easiest to apply as gross multiplying factors to G,(t) although detailed calcula- tion of the dependence of the factors on the photon energies and photon abundances may be required to obtain the mitiplier. The terms to be used are given by G = q Delt) Fpp(t) Len(t) +2, Dzjc,i,(t) : (22) in which D is the relative response of the instrument and q is the "terrain factor". The data treated in Section 4 consists of radiation measurements taken at 3 ft above extended plane sources (or corrected to such a geometry). In addition, all radiation measurements were taken with or converted to the AN/PDR-39(T1B) survey instrument. The value of D.i, for each individual nuclide for this instrument are given in Reference 2. DOE/NW The size of the crater and the amount of earth or debris thrown upward by a detonation of a given yield decreases with the height of | ‘the zero point. For subsurface explosions, the crater size increases as the depth of the zero point increases up to a given depth. Beyond this given depth, the amount of crater material thrown up decreases until such depth of detonation where no crater material is ejected. In the model explosion where all the radioactivity produced is mixed with all the crater material, the variation of M(t) with depth of burst can be expressed as (t) M(t) = rete) 13 (23) L3