Edition 1.0.1 March / 2020
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TechnoAP Co., Ltd.
3.5.
Setting of FAST filter
This board has a FAST filter to obtain time information of waveform acquisition and a SLOW filter to acquire energy
(wave height).
First, set the FAST filter. The setting has the same characteristics as a general timing filter amplifier.
FAST filter (fast diff 50, fast integral 50)
1. DAC output setting
Connect the DAC output signal to the oscilloscope,
select “DAC monitor CH” to the corresponding channel, and set
“DAC monitor type” to “fast”.
Prepare the FAST filter signal from the DAC output of the DSP using an oscilloscope.
2. Constant setting of the FAST system differential circuit
Set the constant of the FAST differential circuit in "fast diff". Select from "ext", "20", "50", "100", "200".
3. Constant setting of FAST system integration circuit
Set the constant of the FAST system integration circuit with "fast integral". Select from "ext", "20", "50", "100", "200".
4. FAST pole zero setting
Adjust the pole zero with “fast pole zero”. The default value is 0. Make settings on the oscilloscope as shown below.
Adjustment is required every time "fast diff" or "fast integral" is changed, but it is not necessary to set as strictly as
SLOW pole zero described later.
Before
“fast polezero” adjustment
After
“fast polezero” adjustment
5. Reference settings
The settings for "fast diff" and "fast integral" differ depending on the detector and signal conditions.
The following is a rough reference example.
Detector
Features
fast diff
fast integral
LaBr3
Rising time fast
20
Ext or 20
HPGe
High resolution
100
100