45
Gamma spectra were determined on plankton from station 42
and on portions of this sample including the formalin preservative filtrate, the Fe (OH), scavenge from the ashed plankton
sample, and the cobalt separation on the same specimen (Fig. 12).
The total plankton sample has a lower n°? component than that
found in sample 54.
12
144 ru’ 106 -R ho
In addition Cet 4 ’*-prt?*,
06
and
gr?°-Nb?> contributes little of the total gamma radiation
(Fig. 12}.
The major part of the gamma activity is contributed
6
59
by Co?! , C028 and Co °, also a limited amount of Fe
is present.
The cobalt in plankton sample 42 ts partly soluble in neutrel formalin and is found in high amount in the filtrate.
eT
though some evidence of the Ce
14 4 pita
planxton curve on the low MEV range,
is
gives only the cor!
Al-
peaks are present in the
the curve on the filtrate
pesk (Fig 12, inset).
This peak is also
shown by the cobalt separation from plankton sample 42 tin the
pre-
same figure.
In summary, the g&mma-spectra findings on non-fission prod-
‘yom
ucts in both the Walton end Marsh plankton samples are as
follows:
Station
gn
1is-
Levels of non-fissionproduct isotopes
Zne>
Walton 8-C
, 11).
Marsh
te
HR Re ti Re
n.d.
low
n.d.
n.d.
54
* +
low
n.d
5
4a
* #
+
n.d.
+ +
FeJ
9-D
55
id
+ +
Cobalt isotopes
+ +t
+ +
4
very high
high
not detected
low
low
+ +
n.d.
n.d.
+