8
F
INE
-
ADJUSTMENT
P
ROCEDURES
:
This section applies only if you are doubtful about the current settings of your detection
system or if you use a non-standard scintillator with different light output from the standard
scintillator.
•
There are 4 different adjustment locations that determine the overall gain of the
detection system:
1. The gain setting of the Handmonitor.
2. The aperture setting of the lens.
3. The gain setting of the CCD camera (see fig. 3).
4. The gain setting of the analog-to-digital converter on the Accumulating
Framegrabber (see fig. 4).
•
Keep in mind that you should optimize for:
1. Best signal-to-noise ratio.
2. Highest dynamic range.
3. Lowest nonlinearities.
4. Highest spatial resolution.
I. If you are primarily using the Accumulating Framegrabber without discrimination and
without further determining the locations of the scintillation events, consider the
following:
That means that you should use a high gain on the image intensifier, because the signal-to
noise-ratio of the image intensifier is only weakly dependent on the gain. The aperture of
the lens should be large (i.e. you should use a low f-number). To adjust the gain of the
ADC Gain
adjustment
Fig. 4: Location of the ADC gain adjustment potentiometer
