The multichannel pulse height
Figure 28 Multichannel Analyzer Output
analyzer is a device that will
separate pulses based on pulse
Each energy range of
pulse height is referred to as a
The pulse height is
proportional to the energy lost by
a gamma ray. Separation of the
pulses, based on pulse height,
shows the energy spectrum of the
gamma rays that are emitted.
Multichannel analyzers typically
have 100 or 200 channels over an
energy range of 0 to 2 MeV. The
output is a plot of pulse height and
gamma activity, as shown in
By analyzing the
spectrum of gamma rays emitted,
the user can determine the
elements which caused the gamma
The operation of a gamma spectrometer is summarized below.
Gamma Spectrometer Summary
A gamma spectrometer uses a scintillation counter, normally NaI.
A multichannel analyzer separates the pulses based on pulse height.
Since each radioactive material emits gammas of certain energy levels, each
pulse height corresponds to a different type of atom.