west drift corrections for each sampling coordinate are given in Column 2.
are taken from Column 10, Table 4.1 and Column 6, Table 4.2.
4.8
Values of C
CALCULATION OF I/A—RATIO OF GAMMA
IONIZATION READINGS TO GAMMA COUNTS
I/A was determined by measuring five water samples from Shot 5. These samples
had sufficient activity for precise measurement in the gamma ionization instrument and
in the UDR—9 gamma counter. The results are shown in Table 4.3. The ratio J/A =
1.59 x 10-8 mv counts~! min was considered applicable to Shot 6 calculations as well,
TABLE 4.3
RATIO OF GAMMA IONIZATION READINGS, I TO GAMMA COUNTS, A
SURFACE WATER SAMPLES FROM SHOT 5
Sampling Position
Latitude
Ix a
Longitude
north
east
Ax =.
mv per 15 cm3*
c/m per 15cem*{
166° 06°
166° 16.6°
0.0057
6.0071
4,250
4,330
12° 00'
166° 13"
0.0151
8,630
166* 08.5!
12° 02.5'
165° 44’
+
.
12° 10°
1l* §5.3'
12° 0s
FOR FIVE
0.0139
0.0095
mv counts~ ‘min
1.34 x 107
1.64 x 10-#
9,400 -
1.48 x 10>
1.75 x 10-®
5,480
1.73 x 1o-§
Mean
1.59 x 107
* Measured on 5/14; corrected to 1200 PST 5/13.
+ Data taken from Column 6, Table 4.1.
due to the similarity in the Shot 5 and Shot 6 sample spectra at the times of analysis.
The ionization measurements made in a 4-pi goemetry high pressure ionization chamber
of the type described by Jones and Overman (Reference 5).
The response of the in-
strument was calibrated‘ with standards whose photon energy and photon emission rate
were known. The response-versus-energy curve for 2.22 x 10° photons min! is shown
in Figure 4.4.
4.4
CALCULATION OF R/I—RATIO OF GAMMA ENERGY EMISSION
RATE PER UNIT AREA TO GAMMAIONIZATION READING PER UNIT AREA
The reader is referred to Table 4.4 for a summaryofthe calculation of RA. The
first and second columns give respectively the mean photon energies Ej and fractional
abundances:
i=9
nj
/
>
i=l
ny
for nine energy intervals as determined by Cook (Reference 2) on samplesof fallout from
Shots 5 and 6.
Spectra were used which were determined at the reference time of analysis
4 private communication from W.E. Shelberg, USNRDL.
63