Nuclide
Factor
Ce?
He”93
Aut
csi?
se“®
0.186
0.282
0.355
0.623
0.884
Co™
K@
Na™4
Shelf
Ww re ee
cm
4
1.000
1.205
Tray distance from bottom of detector when outside
and Cs!"
Calibration procedure: one per day and one following each adjustment of amplifier or detector voltage
Counting procedure: equal counting times for each
series on a given sample
A.2.4 Well Counter.
Nuclear-Chicago Model DS-3
Crystal dimensions and type: 174-inch diameter
x2 inches thick, NaI(T1)
Well dimensions: °*4~inch diameter x 144 inches
deep
A.2.6 Doghouse Counter (Reference 43)
Photomultiplier tube type: 6292 DuMont
Scaler type: Model MPC-1 Berkeley, or Nuclear
Instrument Corporation 162 with Nuclear-Chicago 182
in tandem
Crystal dimensions and type:
Pb shield thickness: 1'4 inches, with °4-inch diam-
Pb shield thickness (counting chamber): 2 inches
Counting chamber dimensions: 20 x 24 x 34 inches
high
Size of hole in roof of counting chamber for detector: 7-inch diameter
Distance from bottom of sample tray to bottom of
crystal: 36 inches
Sample tray dimensions: 18 x 21 x 2 inches deep
Counting efficiency for several point-source nu-
Relative
Count Rate
pet
100
99.2
3.9 (~ well depth)
90.6
Efficiency for several nuclides:
Nuclide
.
OT,
Anis
Co™
ps
inch thick
Photomultiplier tube type: 6292 DuMont
Scaler type: Model 162 Nuclear Instrument Corporation, and Model 182 Nuclear-Chicago (in tandem)
Pb shield dimensions (detector): 10-inch diameter
x 20 inches high x 114 inches thick
(15 x 125 mm):
1.81
1l-inch diameter x 1
inch thick, Nal(T1), Harshaw aluminum absorber ‘4-
eter hole above crystal well; additional 2-inch thickness in YAG 40 laboratory
Counting rate versus sample volume in test tube
0.01
2.07
4.76
5.25
6.84
of 4-inch diameter collimator: 13.95 cm
Calibration standards: Ba’, Ce! Hy3 Na”,
1.312
Sample
Volume
ml
Distances
clides, centered in bottom of tray with '4-inch aluminum cover in place:
Efficiency
counts /dis
Nuclide
counts/dis x 107
0.42
Na
Na
1.70
0.936
0.51
se4*
1.16
——
k#
0.43
Co*
Nb"
Ca87_pais™m
Cel!
Aut
He**3
Minimum count rate requiring coincidence loss
correction: 1.0 x 10® counts/min
Counting procedure: minimum of 10‘ counts to
Maintain a statistical error of ~ 1.0 percent
A.2.5 20-Channel Analyzer.
0.151
1.02
0.506
0.548
0.622
0.711
0.842
Relative counter photon efficiency, computed for
total aluminum thickness = '4 inch (3.43 gm/cm’):
Crystal dimensions and type: 2-inch diameter x 2
inches thick, Nal(T1)
Glow transfer tube types: GC-10B and GC-10D
Fast register type: Sodeco
Voltage gain (with delay line pulse shaping): 1,000
Attenuation (with ladder attenuator): 63 decibels in
I~decibel steps
Pb shield thickness: ~2 inches
Counting chamber dimensions: 8-inch diameter
«34 inches high
Shelf distances from bottom of detector:
163
Energy
Mev
Efficiency
pet
0.01
0.02
0.03
0.05
0.07
0.10
0.15
0
0.0034
3.24
33.3
48.7
57.8
63.7