Difference between revisions of "HRRL 7-31-09"

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==TDC Calibration==
 
==TDC Calibration==
  
 +
Second pulse width is 80 ns.
  
 +
;Conclusion
 +
 +
In order to get actual time between the start and the stop pulse, one needs to subtract the width of the second signal. In this case it was 80 ns. 
  
 
{| border="1" cellpadding="20" cellspacing="0"
 
{| border="1" cellpadding="20" cellspacing="0"
 
|-
 
|-
−
| Run Number || Scope Image || TDC Histogram || Calculated Time (ns)
+
| Run Number || Scope Image || TDC Histogram || Calculated Time (ns) || Time measured on the scope ns (between the fall of the first pulse and rise of the second pulse) || Time measured on the scope ns (between the fall of the first pulse and fall of the second pulse) || Pulse width (ns)
 +
|-
 +
| 1238 || [[File:imageTDCCalibration_1.png|200px]] || [[File:imageTDCCalibration_1.gif|200px]] || 169.5 || 160 || 80 || 80
 
|-
 
|-
−
| 1238 || [[File:imageTDCCalibration_1.png|200px]] || [[File:imageTDCCalibration_1.gif|200px]] ||  
+
| 1239 || [[File:imageTDCCalibration_2.png|200px]] || [[File:imageTDCCalibration_2.gif|200px]] || 135.7 || 130 || 50 || 80
 
|-
 
|-
−
| 1239 || [[File:imageTDCCalibration_2.png|200px]] || [[File:imageTDCCalibration_2.gif|200px]] ||  
+
| 1240 || [[File:imageTDCCalibration_3.png|200px]] || [[File:imageTDCCalibration_3.gif|200px]] || 111.5 || 110 || 30 || 80
 
|-
 
|-
−
| 1240 || [[File:imageTDCCalibration_3.png|200px]] || [[File:imageTDCCalibration_3.gif|200px]] ||  
+
| 1328 || [[File:imageTDCCalibration_4.png|200px]] || [[File:imageTDCCalibration_4.gif|200px]] || 122 || 120 || -50 || 170
 
|}
 
|}
  
 
==Actual Measurements==
 
==Actual Measurements==
 +
 +
 +
We had runs for different beam energy (2 && 4 MeV) and collimator size(~0.2 && ~0.8 cm).<br>
 +
Table below shows TDC measurements for all cases for Metalica and Plastika.
  
 
{| border="1" cellpadding="20" cellspacing="0"
 
{| border="1" cellpadding="20" cellspacing="0"
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|TDC Histogram
 
|TDC Histogram
 
|-
 
|-
−
| 1296 || 2 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1296.gif|250px]]
+
| 1296 || 2 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1296.gif|200px]][[File:TDCSpectrum_1296_1.gif|200px]]
 
|-
 
|-
−
| 1297 || 4 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1297.gif|250px]]
+
| 1297, 1298 && 1299 || 4 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1297_8_9.gif|200px]][[File:TDCSpectrum_1297_8_9_1.gif|200px]]
 
|-
 
|-
−
| 1298 || 4 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1298.gif|250px]]
+
| 1304 && 1305 || 4 || 0.2 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1304-1305.gif|200px]][[File:TDCSpectrum_1304-1305_1.gif|200px]]
 
|-
 
|-
−
| 1299 || 4 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1299.gif|250px]]
+
| 1306 || 2 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1306.gif|200px]][[File:TDCSpectrum_1306_1.gif|200px]]
−
|-
 
−
| 1304 && 1305 || 4 || 0.2 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1304-1305.gif|250px]]
 
−
|-
 
−
| 1306 || 2 || 0.8 || 1400:-700:980 || 50 || [[File:TDCSpectrum_1306.gif|250px]]
 
 
|}
 
|}
 +
 +
 +
Plastika - 120 ns, Metalica - 170 ns.
 +
 +
[[File:HRRL_7-31-09_MetalicaPlastika_Start.png|250px]][[File:HRRL_7-31-09_MetalicaPlastika_Start_1.png|250px]]
 +
 +
 +
;Example
 +
 +
[[File:TDCSpectrum_1304_5_gaussian_fitting.gif|200px]]
 +
 +
For Metalica on the TDC histogram mean value is 307, but the time between the pulse of the PMT+RFGate and Metalica is 307-170=137 ns.
 +
For Plastika it is 226.4-120=106.4ns. So time difference between this two pulses is around ~30 ns(the same on the scope).
 +
 +
 +
The drift velocity for electrons in drift chambers is ~ 50μm / ns. [[Media:mestayer.pdf]]
 +
[edit] Calculated result using TDC data
 +
 +
The size of the drift chamber cell is 0.86 cm.
 +
 +
<math>Time = \frac{1000 {\rm ns}}{2^{12}{\rm chan}} \times  {\rm chan} ns</math>
 +
 +
<math>{t_{Drift}}^{maximum} = \frac{CellSize}{v_{Drift}} = \frac{0.86 \times 10^{-2} m}{50 \mu m/ns} = 172 ns</math>
 +
 +
So the maximum drift time in DCs(Metalica && Plastika) can be 172 ns.
 +
 +
Our data(above example) shows that for Metalica it is ~137+/-100ns and for Plastika it is ~106+/?
  
 
=VFAT runs=
 
=VFAT runs=
Line 154: Line 187:
  
 
[[File:Pb_Attenuation_Photon.pdf]]
 
[[File:Pb_Attenuation_Photon.pdf]]
 +
 +
=Experimental Setup=
 +
 +
[[File:0-8cm_collimator.jpg|250px]][[File:0-2cm_collimator.jpg|250px]]
 +
 +
[[File:Detectors_7-31-09_HRRL_ExperimentSetup.gif|850px]]
 +
 +
 +
[[File:Detectors_7-31-09_HRRL_ExperimentSetup_1.jpg|550px]]

Latest revision as of 20:22, 12 August 2009

Default HRRL running Conditions

[math]I_{peak}[/math] Pulse Width Rep Rate Energy
8 mA 100 ns 1 Hz 3 MeV


cable names

CH ID Description
2223A1 Front Scintillator
2223A2 Rear Scintilaltor
2223A3 ADC Gate From counting house to Experimental Cell
2223A4 TDC start pulse from counting house to experimental cell (PMT front + beam Gate)
2223A5 Coincidenc between front + rear Scint + Gun pulser to scaler channel 8
2223A6 Metalica sense wire 4
2223A7 Delayed rear PMT pulse to ADC
2223A8 Plastica sense wire 4
2223A9 Plastica to scaler channel 4
2223A10 Front scintillator to ADC
2223A11 Metalica scaler channel 1
2223A12 DAQ trigger


DAQ Ntuple names

Ntuple Variable Description
ADC5 Front Scintilator
ADC1 Metalica sense wire 4
ADC16 Rear Scintilator
ADC13 Plastica sense wire 4
TDC1 Metalica sense wire 4
TDC3 Plastika sense wire 4

ADC + Scaler + TDC + V1495

Run Number Distance to Metallica's Feedthrough tip (cm) Metalica scaler counts scaler ch 4 Plastika Scaler Counts scaler ch 1 Rear PMT + Front PMT + Gun Pulse Counts Scaler Ch 8 HV S:F:G Discriminator (mV) Metalica counts/PMT+Gun pulse
1263 19 0 1400:-700:980 50

TDC Measurements

TDC Calibration

Second pulse width is 80 ns.

Conclusion

In order to get actual time between the start and the stop pulse, one needs to subtract the width of the second signal. In this case it was 80 ns.

Run Number Scope Image TDC Histogram Calculated Time (ns) Time measured on the scope ns (between the fall of the first pulse and rise of the second pulse) Time measured on the scope ns (between the fall of the first pulse and fall of the second pulse) Pulse width (ns)
1238 ImageTDCCalibration 1.png ImageTDCCalibration 1.gif 169.5 160 80 80
1239 ImageTDCCalibration 2.png ImageTDCCalibration 2.gif 135.7 130 50 80
1240 ImageTDCCalibration 3.png ImageTDCCalibration 3.gif 111.5 110 30 80
1328 ImageTDCCalibration 4.png ImageTDCCalibration 4.gif 122 120 -50 170

Actual Measurements

We had runs for different beam energy (2 && 4 MeV) and collimator size(~0.2 && ~0.8 cm).
Table below shows TDC measurements for all cases for Metalica and Plastika.

Run Number Beam Energy (MeV) Collimator size ~ (cm) HV S:F:G Discriminator Threshold (mV) TDC Histogram
1296 2 0.8 1400:-700:980 50 TDCSpectrum 1296.gifTDCSpectrum 1296 1.gif
1297, 1298 && 1299 4 0.8 1400:-700:980 50 TDCSpectrum 1297 8 9.gifTDCSpectrum 1297 8 9 1.gif
1304 && 1305 4 0.2 1400:-700:980 50 TDCSpectrum 1304-1305.gifTDCSpectrum 1304-1305 1.gif
1306 2 0.8 1400:-700:980 50 TDCSpectrum 1306.gifTDCSpectrum 1306 1.gif


Plastika - 120 ns, Metalica - 170 ns.

HRRL 7-31-09 MetalicaPlastika Start.pngHRRL 7-31-09 MetalicaPlastika Start 1.png


Example

TDCSpectrum 1304 5 gaussian fitting.gif

For Metalica on the TDC histogram mean value is 307, but the time between the pulse of the PMT+RFGate and Metalica is 307-170=137 ns. For Plastika it is 226.4-120=106.4ns. So time difference between this two pulses is around ~30 ns(the same on the scope).


The drift velocity for electrons in drift chambers is ~ 50μm / ns. Media:mestayer.pdf [edit] Calculated result using TDC data

The size of the drift chamber cell is 0.86 cm.

[math]Time = \frac{1000 {\rm ns}}{2^{12}{\rm chan}} \times {\rm chan} ns[/math]

[math]{t_{Drift}}^{maximum} = \frac{CellSize}{v_{Drift}} = \frac{0.86 \times 10^{-2} m}{50 \mu m/ns} = 172 ns[/math]

So the maximum drift time in DCs(Metalica && Plastika) can be 172 ns.

Our data(above example) shows that for Metalica it is ~137+/-100ns and for Plastika it is ~106+/?

VFAT runs

4 MeV beam energy, big collimator.

GEM HV settings: [math]V_{Drift}/V_{GEM}[/math]=3425/3125.

Run Number Card 1 Threshold Card 2 Threshold
1300 151 116
1301 153 118
1302 155 120
1303 157 122

GEM HV settings: [math]V_{Drift}/V_{GEM}[/math]=3425/3125.

4 MeV beam energy, small collimator.

Run Number Card 1 Threshold Card 2 Threshold
1305 151 124

File:Pb Attenuation Photon.pdf

Experimental Setup

0-8cm collimator.jpg0-2cm collimator.jpg

Detectors 7-31-09 HRRL ExperimentSetup.gif


Detectors 7-31-09 HRRL ExperimentSetup 1.jpg

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