9-7. A series of radioactive samples of short half-life will be counted one
per day over several days. Explain how variations in the observed
counts caused by fluctuations in the sensitivity of the counting
system can be compensated.
9-8. A pulse height spectrum for 131I (γ ray of 0.393 MeV) was obtained
with a single-channel pulse height analyzer calibrated from
0 to 500 keV. The window width was 2%. Describe the changes in
the spectrum if
a. A 5% window were used
b. The amplifier gain were twice as great
c. The amplifier gain were half as great
d. The upper discriminator of the window were removed
