effect by considerin; the sreater effect an integrating time
constant,
such as
pulse heights.
10
is used in the count rete meter, has on low,
No mechanism to explain the former effect
suggests itself, however, and the fact that fair asreement
exists in most cases between comparable 60-kev and 280-kev
lines leads one to doubt the existence of a consistent energydependent machine effect to explain the discrepancies.
It may be that the disagreements are largely due to
resolution problems in the low energy region of the standard
gain records, since in many cases the areas could be brought
closer to agreement by taking from one line and adding to
an adjacent line.
-
This problem is especially troublesome in
trying to separate the 60, 105, and 140 kev lines on the
standard gain records.
A discussion of the overall performance of the system
in analyzing the standard sources, including the consistency
of the results,is found in Appendix I.
DISCUSSION
It 1s of special interest to note the presence of Na**
activity in both the Zuni and Navaho cloud samples (the only
samples to reach this section soon enough for such detection
were the cloud samples from each shot).
This activity is
evident from the 1.37-and 2.75-Mev total absorption peaks
detectable on the first two or three recordings made with
25
a