Table
Date
4.
Average Annual Americium Values
24lam x 1076 atoms/SCM
2414m/239pu atom ratio
1963
5.92
0.0011
1964
2.68
0.0012
1965
1.91
0.0023
1966
1.00
0.0025
1967
0.62
0.0027
1968
0.49
0.0012
1969
0.33
0.0014
1970
0.27
0.0007
266
indicates that ingrowth
in 1967 with an apparent half-life of 1.6 years. This
atmosphere. From
from decay of 241py ig a negligible source of 24lam in the
the injections of
1967-1970, the 241am/239Pu atom ratio decreased because
.
plutonium contained relatively smaller quantities of americium
ACKNOWLEDGMENTS
V. Hamilton of the
Thanks are given ta SSgt Thomas W. Nibarger and Howard
separating and purifying
Chemistry Section of McClellan Central Laboratory for
Special thanks are given to
the plutonium samples reported in this study.
this manuscript.
Mrs. Marcene Beckinger for her help in the preparation of
267