r
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a
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_ 7.
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-
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=
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r
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SES
7
nae
this can be done by summation of hodograph winds if these aro more readily
accessible,
Likewise, tho distances from the altitude points on the
hodozraph to points of fall-out interest can be quickly measured with the
ruler, giving tho valucs of r, Knowing S and r, cne can easily compute
pandq.
With the aid of a family of curves of
j 9m (q)* vs q
(p)?
(sce Fiz. 1) for several values of p, one ean rapidly interpolate the
values that mst be added up at any loesticn.
The cxponontial factor
ev
Ma
men
drops off very rapidly with q, and after working out 2 few cases, one can
tell, from an inspecticn of the hodogr=ph-on-atcll rlot, some of the
altitude points that can be nezleected in the ecmputaticn.
6.
Fige 2 amd Table 1 illustrates the application of the method to
Vv NECT.L2 shot, using the winds observed at shot time.
The points on Fiz. 2
marked 10, 20, 30, are the 10,000 ft, 20,000 ft, - - — altitude points on
the hodozraph for particles fallinz 50,000 ft per hour.
«4 particle
starting, for example, at 30,000 ft above ground zero, and falling under
the influence of winds but not diffusion, would land at the point marked 30.
The value of S, the horizontal distance travelled, is estimated by summing
the distance between the suceessive points from ground zero to point 30.
In calculating q in Table 1, some values are omitted as beyond the ranze
of Fiz. 1. More values ere dropped, as too small to bether with, in
enteri
the
quentitics
-
mene
ee
= 8 (a)3. The final totels are the surface
P
Concentrations that would be produced if the initial central concentra,tions
(C,) were all unity.
When the method was tried out on YNKES, ‘it was found
that if the resultant surface emcentrations wore mltiplied by 100, they
agree reasonably well with the dose rate, in roentgcns per hour, measured
one day after the shot.
This factor was used in making up Table 2, and it
appears to jive fairly zood results for Bu.VO, ROMEO, and UNIQHW also,
élthoush there is same tendency to over-estimate the lower dose rates at
the larger distances. In Table 1, however, it is clear that the agrcement
1s about as good as in Table 2 without miltiplyin= by a foctor of 100. The
vield of NECT.2 was less than that of the shots in Table 2, but not by a
| factor of 100, it the present tine the only explanation that can be
offored for this discrepancy is tho heavy rain that occurred on NECT.si day.
7. There is zood reason to anticipate that the current detailed
study of the more complex method will yield a better simplified technique
than the above. For this reason, there is little justification for a ncre
elaborate report on the method at this time.
UNCLASSIFIED