of the Shot 6 water samples (7 days) and as close to the time of analysis of Shot 5 samples
(9 days) as possible.
Column 3 lists the response of the gammaionization instrument for 2.22 x 10° gamma
photons min-! of energy Ej as determined from the curve in Figure 4.4.
In calculating Columns 4 and 5, a source was arbitrarily chosen equivalent to
2.22 x 10° photons min-! em~? of all energies.
5
8
T
T
T
T
T
Column 4 then gives for each value of Ej
T
© DETERMINED WITH Hg2°Eay= 0.24 MEV
w
*A DETERMINED WITH. Co-Ba!3? Egy-O0.62MEV
5
“@ DETERMINED WITH Fe5® , Egy: 1.20 MEV
Z 6}— “O DETERMINED WITH Co® , Egy: 1.25 MEV -- -— —
z
2
o St
“Shetberg WE. ,
Shipmon,W.H. and LCOR RK Skow
a
3
Oy;
2
ot;
n 2
.
or
t
|
-~ >:
ope
4
ee
ae
~- fee
o
of
—4q
|
7 f--~
ot
02
+
}_
ws
zo
|
oh
oa
s
S
—"
—T
ne
3 4
2
g
;
W DETERMINED WITH No2* Egy: 2.07 MEV
2
——
|.
3 {| cM DETERMINED WITH I!9! Egy? 0.39 MEV _
O03
04
O5
O06
O7
O8
.
O98
10
Hf
2
PHOTONENERGY, E; (MEV)
03
t#
i
%JS
16.47
18
t?
20
Figure 4.4 Relative response of NRDL ion chamber with incident
photon energy (Mev) (after Shelbert).
the calculated gamma ionization instrument response in mv cm~? for 2.22 x 108 gamma
photons min~'!cm-?. Column 5 gives the corresponding gamma energy rate in Mev
min-! em-? for
i=9
2.22 x 108 x nj/
i
1
photons of energy Ej in Mev min-! cm -2
The ratio of the Columns 5 and 4then gives for
both Shot 5 and Shot 6:
x = 3.75 x 108 Mev min-!mv-!.
4.5
CALCULATION OF REFERENCE DOSE RATE, dr
The value of dy corresponding to a gamma energy emission rate R = 1 Mev
min-! cm~?, was calculated from Equations 4.1 and 4.2 and the gamma spectra and
67