FOOTE
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fr es re ee ee ee ee
me ee ee ee ee ee ee ee ee ee
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COUNTS/ CHANNEL
Cae
186
CHANNEL NUMBER
Fig. 3—Method of locating photopeak positions. k’', maximum count
channel; k”, photopeak center, even-channel location; and k, computed
bhotopeak, center location.
solution for their intersection is assumed to be the peak location. This
manner of peak locating has proved to require little computer time and
is consistent to about +0.2 channelat channel 185. The lower energyline
selected has varied, depending upon the intensity of energy lines that
might overlap others. The 0.751-Mev line from *Zr—*Nb was used
initially because of the superposition of the “’Laline at 1.60 Mev overlapping the “°K line at 1.46 Mev.
After calibration using two photopeaks, the total spectrum is corrected, channel by channel, to be even-channel-corrected for precise
energy calibration. If noncorrected field data were utilized, errors
would result for */‘Bi, as shown in Fig. 4. This figure shows the loca-