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User name R. Michaels
Log entry time 12:49:26 on February20,2013
Entry number 385793
keyword=Asymmetry Test CircuitHere is a circuit to test the ability of the Compton DAQ to
extract an asymmetry of between 0.1 and 4% for rates between
200 kHz and 2 MHz. This is for the new FADC Counting DAQ.
The V2F has a calibration f (kHz) = 200 + 210 * V, where V
is in volts and must be positive. Note a pedestal of 200 kHz.
The helicity (NIM) subtracts from a +3.5 V offset at a Sum/Amp.
This is then reduced by an offset/atten channel and fed to the V2F.
A random pulser is mixed with the result of the V2F to form the
fake signal which has a helicity-correlated asymmetry that is tunable.
No results from the FADC yet, just the circuit which I've checked
with a scope. It uses existing NIM modules.
FIGURE 1
