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| Line 170: |
Line 170: |
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| | ===Changing cell size=== | | ===Changing cell size=== |
| − | Noting the difference from the spacing for a single cell, to the entire detector layer
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| − | <center><math>0.00524-0.00561=0.00037\ \approx .001\ radians</math></center>
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| − | Determining by how much each increment between each wire's corresponding angle must deviate from the starting distance between wires to the end of the wires:
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| − | <center><math>\frac{0.00037\ radians}{112\ wires}=4\times 10^{-2} \frac{radians}{wire}</math></center>
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| − | An uncertainty of this magnitude in radians corresponds to an angular uncertainty of
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| − | <center><math>.001\ radian\ \frac{180^{\circ}}{\pi\ radians}\approx .0573^{\circ}</math></center>
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| − | Testing this for a random angle, 78 degrees we find
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| − | <center><math>0.00558\times 78\ = 0.43524\ radians \frac{180^{\circ}}{\pi\ radians}\approx 24.94^{\circ}</math></center>
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| − | Adding this to the starting angle of 4.91 degrees
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| − | <center><math>4.91^{\circ}+24.94^{\circ}=29.85^{\circ}\pm .0573^{\circ}</math></center>
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| − | Comparing this to CED at wire 78
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| − | <center>[[File:Layer1Wire78.png]]</center>
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| − | <center><math>\Longrightarrow 29.85^{\circ}\pm .0573^{\circ}\approx 29.88^{\circ}</math></center>
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| − | ==Super Layer 1:Layer 2==
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| − | For a hit at layer 2, wire 1 we find the corresponding angle theta in the lab frame to be 5.00 degrees
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| − | <center>[[File:Superlayer1_layer2_wire1.png]]</center>
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| − | Examing a hit at layer 2, wire 112 we find the corresponding angle theta in the lab frame to be 41.05 degrees
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| − | <center>[[File:Superlayer1_layer2_wire112.png]]</center>
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| − | This sets the lower limit:
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| − | <center><math>\frac{5.00^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.0872664626\ radians\approx 0.0873\ radians</math></center>
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| − | This sets the upper limit:
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| − | <center><math>\frac{40.70^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.716457657944\ radians\approx 0.716\ radians</math></center>
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| − | Taking the difference,
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| − | <center><math>.716457657944-..0872664626\approx\ .629\ radians</math></center>
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| − | Dividing by 112, we find
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| − | <center><math>\frac{.629191195344}{112}=.00561777853\ radians\approx\ 0.00562\ radians</math></center>
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| − | ==Super Layer 1:Layer 6==
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| − | For a hit at layer 6, wire 1 we find the corresponding angle theta in the lab frame to be 5.30 degrees
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| − | <center>[[File:Superlayer1_layer6_wire1.png]]</center>
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| − | Examing a hit at layer 6, wire 112 we find the corresponding angle theta in the lab frame to be 40.61 degrees
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| − | <center>[[File:Superlayer1_layer6_wire112.png]]</center>
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| − | This sets the lower limit:
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| − | <center><math>\frac{5.30^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.09250245\ radians\approx 0.025\ radians</math></center>
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| − | This sets the upper limit:
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| − | <center><math>\frac{40.61^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.7087782\ radians\approx 0.709\ radians</math></center>
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| − | Taking the difference,
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| − | <center><math>.716457657944-.0872664626\approx\ .616\ radians</math></center>
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| − | Dividing by 112, we find
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| − | <center><math>\frac{.61627575}{112}=.00550246\ radians\approx\ 0.00550\ radians</math></center>
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| − | ==Superlayer 2:Layer 1==
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| − | <center>[[File:Superlayer2_layer1_wire1.png]]</center>
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| − | <center>[[File:Superlayer2_layer1_wire112.png]]</center>
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Determining wire-theta correspondance
To associate the hits with the Moller scattering angle theta, the occupancy plots of the drift chamber hits by means of wire numbers and layer must be translated using the physical constraints of the detector. Using the data released for the DC:
DC: Drift Chambers(specs)
This gives the detector with a working range of 5 to 40 degrees in Theta for the lab frame, with a resolution of 1m radian.
This sets the lower limit:
[math]\frac{5^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.0872664626\ radians[/math]
This sets the upper limit:
[math]\frac{40^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.698131700798\ radians[/math]
Taking the difference,
[math].698131700798-.0872664626\approx\ .61086523198\ radians[/math]
Dividing by 112, we find
[math]\frac{.61086523198}{112}=.005454153912\ radians\approx\ 0.0055\ radians[/math]
CED Verification
Using CED to verify the angle and wire correlation,
Zooming in on the view paralell to the direction of the wires in ced, we can examine the wire corresponding theta angle in the drift chamber.
Corresponding theta angles can be found for other wires, in Region 1, Superlayers 1 and 2.
Table 1: Superlayer 1 Wire-Angle Theta Correspondence in Degrees
| Wire Number
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Layer 1
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Layer 2
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Layer 3
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Layer 4
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Layer 5
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Layer 6
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| 1
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4.79
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5.03
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4.98
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5.22
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5.16
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5.40
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| 2
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5.09
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5.33
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5.27
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5.51
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5.45
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5.69
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| 78
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29.79
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29.93
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29.74
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29.88
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29.69
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29.83
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| 111
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40.50
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40.59
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40.36
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40.44
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40.21
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40.29
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| 112
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40.82
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40.90
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40.67
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40.75
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40.52
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40.60
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Table 2: Superlayer 2 Wire-Angle Theta Correspondence in Degrees
| Wire Number
|
Layer 1
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Layer 2
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Layer 3
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Layer 4
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Layer 5
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Layer 6
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| 1
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4.79
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5.03
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4.98
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5.22
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5.16
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5.40
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| 2
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5.09
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5.33
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5.27
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5.51
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5.45
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5.69
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| 78
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29.79
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29.93
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29.74
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29.88
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29.70
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29.84
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| 111
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40.51
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40.59
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40.36
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40.44
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40.22
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40.30
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| 112
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40.82
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40.90
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40.67
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40.75
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40.52
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40.60
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Super Layer 1:Layer 1
Finding the difference between wires 1 and 2,
[math]5.09-4.79=.3^{\circ} \frac{\pi\ radians}{180^{\circ}}=0.005235987756\approx\ 0.00524\ radians[/math]
Examing a hit at layer 1, wire 112 we find the corresponding angle theta in the lab frame to be 40.82 degrees
This sets the lower limit:
[math]\frac{4.79^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.083601271171\ radians\approx 0.0836\ radians[/math]
This sets the upper limit:
[math]\frac{40.82^{\circ}}{1}\frac{\pi\ radians}{180^{\circ}}=.712443400664\ radians\approx 0.712\ radians[/math]
Taking the difference,
[math].712443400664-.083601271171\approx\ .629\ radians[/math]
Dividing by 112, we find
[math]\frac{.628842129493}{112}=.00561466187\ radians\approx\ 0.00561\ radians[/math]
Changing cell size
