Time over Threshold Electronics for Neutrino Telescopy
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Transcript of Time over Threshold Electronics for Neutrino Telescopy
Time over Threshold Time over Threshold Electronics for Neutrino Electronics for Neutrino
TelescopyTelescopy
George BourlisGeorge Bourlis
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multiplicity
ReadOut Electronics
GPS Input
USB PortTrigger Output5 PMT Signal Inputs
25ps accuracy TDC
HPTDC
• 32 channels (LR) – 8 Channels (HR)
•25ps (HR) to 100 ps (LR) accuracy
•Self Calibrating
ReadOut Electronics
EZ-USB FX2 HPTDC CONTROL
Card Debugging Configuration
Trigger
Input
splitter
splitter
discriminator
- Offset of each input
- Scale of each input
- Timing among input channels
Sample PulsesInput 1
Sample PulsesInput 1
Sample PulsesInput 1
The Photomultiplier Tube:
PH: XP1912
Charge (pCb)
Single p.e
Gain vs HV
Calibration
@ “nominal” H.V.
gain: ~ 4 105
<charge>/p.e. ~ 0.07pCb
<pulse height>/p.e. ~ 1.05mV
Rise Time: 1.2 ns
Charge (in units of mean p.e. charge)
At the Detector Center
Data
- Monte Carlo Prediction
Charge versus Time Over ThresholdC
ha
rge
(p
C)
Time Over Threshold (s)
1st Threshold only 1st & 2nd Threshold 1st, 2nd & 3rd Threshold
4mV
50mV
15mV
Charge Parameterization
1st & 2nd Threshold 1st, 2nd & 3rd Threshold
kkCharge= a (tot)
Charge Estimation
1st & 2nd Threshold 1st, 2nd & 3rd Threshold
Measured Charge - Estimated Charge
Measured Charge
11% 8%
- Estimated Resolution ~10%
- Better if all thresholds are crossed
Charge Estimation
1st & 2nd Threshold 1st, 2nd & 3rd Threshold
Measured Charge - Estimated Charge
Estimated Error
- σ=(1.01 ± 0.01) (2 thresholds)
- σ=(1.1 ± 0.1) (3 thresholds)
Time (ns)
Trigger
Input