Table 2.
a
—
»
‘
0-5
.
Exponential
“Ba La
RyRh
32r-Nb
oK
6,000
»
35,000
o
Uniform
26,000
5,a50
”
1B (U series)
2°8T1 (Th scries)
1-76
2-82
,
Dus#-RATE CALIBRATION OF SPECTROMETER
Peak counta/pr./b
Source
Isotope
1° Ru-™*Rh
075
1-48
,
“
Peak energy (MeV)
of
_
”
”
18,900
Ton
700
10°
~
0.75 MEV.
,
Zr 95
10*
-
.
a)
ut
.
ne day
t
ey
.
.
K 40
z
“yee
2
2 10
,
~
1.46 MEV.
:
eo
.
y
ct oo,
Nb 95
‘
*
3
5
2
2.62 MEV
TI208
407
.
ot
0
Ltt tp pti py tf
20
40
60
80
l
100 120 140 160 180 200 220 240 260
Channel No.
Fig. 1. Two typical field spectra obtained during late 1962. Top curve :
Colorado Springs, Colo., October 11, 1962; bottom curve: Argonne,
Ill, October 15, 1962. The cosmic ray, natural and fall-out levels are
all somewhathigher at the Colorado Springs location
difference between the total y-dose rate, as measured by
the spectrometer and ionization chamber, and the natural
y-dose rate, as determined by the peak or energy-band
analysis.
A second method involves the determination
of theareas of the 0-5- and 0-75-MeVtotal absorption peaks
4