|
| |
Back
Figure 26 Photomultiplier Tube Schematic Diagram | Up
Instrumentation and Control 2 of 2 | Next
GAMMA SPECTROSCOPY |
SCINTILLATION COUNTER
Radiation Detectors
Summary
The operation of scintillation counters is summarized below.
Scintillation Counter Summary
Radiation interactions with a crystal center cause electrons to be raised to an
excited state.
When the center de-excites, the crystal emits a photon in the visible light range.
Three classes of phosphors are used: inorganic crystals, organic crystals, and
plastic phosphors.
The photon, emitted from the phosphor, interacts with the photocathode of a
photomultiplier tube, releasing electrons.
Using a voltage potential, the electrons are attracted and strike the nearest dynode
with enough energy to release additional electrons.
The second-generation electrons are attracted and strike a second dynode,
releasing more electrons.
This amplification continues through 10 to 12 stages.
At the final dynode, sufficient electrons are available to produce a pulse of
sufficient magnitude for further amplification.
IC-06
Page 48
Rev. 0
|
