Title: A Study of Time over Threshold TOT Technique for Plastic Scintillator Counter
1A Study of Time over Threshold (TOT)
Techniquefor Plastic Scintillator Counter
2Outline
- Introduction
- Research method-wave analysis
- Signal characteristics
- Relative charge resolution by TOT
- Summary
3Introduction to TOT (1)
TOT-Time Over Threshold Pulse width TOT is
somewhat dependent the charge Different
threshold Advantage One of alternatives to
charge measurement Simplify the
electronics Reduce the cost
Time over threshold
4Introduction to TOT (2)
- Apply in gas detectors
- Multi-gap Resistive Plate Chamber of
- ALICE and STAR
- NINO-Correction of front edge time walk
- Drift Chamber of CLEO-III
- Relative charge resolution 10
- TOT for Plastic scintillator counter?
- The correlation between TOT and Charge?
- Relative charge resolution?
TOT versus measured time
Relative Charge resolution of CLEO
5Research method-wave analysis
- To be measure TOT, Amplitude, Charge
- How?
- Chip?
- Based on CAMAC system?
- Wave analysis
- Using high quality oscilloscope
- sample rate 20 GS/s
- TOF module
- Scintillator EJ200 R5924
Experimental setup
6Pedestal, Noise, Rise time
The data within the first 250 ns are noise
without any particle passing through the
scintillator counter Noise 2.0 mV Pedestal 2.2
mV Rise time4.2ns
A wave shape of pulse
Reference to the design BESIII TOF electronics
The noise spectrum
Spectrum of rise time
7Amplitude, Charge
The charge is obtained from the time integral of
the current pulse
Spectrum of charge
Spectrum of amplitude
Charge versus amplitude
8Distribution of TOT
The distribution of TOT with different threshold
The distribution of TOT when the threshold is set
to 65 mV 15 of the most probable value of
amplitude
The distribution of TOT when the threshold is set
to 195 mV 45 of the most probable value of
amplitude
9TOT VS Charge--threshold 65mV
Linear correlation between TOT and charge
Relative charge resolution can reach 7-18 when
the threshold is set to 65mV
TOT versus charge
The relative error of Q by TOT can be obtained by
formula
The relative charge resolution versus charge
10TOT VS Charge--threshold 195mV
The correlation between TOT and charge
TOT versus charge
Relative charge resolution can reach 4-7 when
the threshold is set to 195mV
The relative charge resolution versus charge
11Summary
- A Study of TOT technique for Scintillator counter
firstly - Wave analysis
- The Characteristics of TOF module
- Pedestal, Noise, Amplitude, Charge, Rise time
- Relative charge resolution
- From 7 to 18 (Threshold is set to 65mv)
- From 4 to 7 (Threshold is set to 195mv)
12Thanks