Difference between revisions of "Specification for broad-band tagging hodoscope"

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 +
[[Image:TAGH-from-magnet-all.jpg|900px|]]
 +
 
In its standard configuration the fixed-array hodoscope consists of 218 scintillators distributed over 9.1 m behind the focal-plane of the tagger spectrometer. Standard configuration refers to a coherent-peak setting at 9.0 GeV, i.e. the microscope covers the energy range 8.1&lt;E<sub>&gamma;</sub>&lt;9.1 GeV.  
 
In its standard configuration the fixed-array hodoscope consists of 218 scintillators distributed over 9.1 m behind the focal-plane of the tagger spectrometer. Standard configuration refers to a coherent-peak setting at 9.0 GeV, i.e. the microscope covers the energy range 8.1&lt;E<sub>&gamma;</sub>&lt;9.1 GeV.  
  
 
Tagging range (for a 12 GeV electron beam):  
 
Tagging range (for a 12 GeV electron beam):  
* <b>Photons between 3.0 GeV and 8.1 GeV</b>: detector positions correspond to 60 MeV steps in E<sub>&gamma;</sub> with <b>30-50% sampling</b>. The counter widths are chosen such that the typical rate per counter is limited to 3-4 MHz at 10<sup>8</sup> &gamma;/sec on target;  
+
* <b>Photons between 3.0 GeV and 8.2 GeV</b>: detector positions correspond to 60 MeV steps in E<sub>&gamma;</sub> with <b>30-50% sampling</b>. The counter widths are chosen such that the typical rate per counter is limited to 3-4 MHz at 10<sup>8</sup> &gamma;/sec on target;  
* <b>Photons between 9.1 GeV and 11.78 GeV</b>: scintillators cover the full energy range, counter widths were calculated such that the typical rate per counter is limited to 1-4 MHz at 10<sup>8</sup> &gamma;/sec on target.  
+
* <b>Photons between 9.2 GeV and 11.78 GeV</b>: scintillators cover the full energy range, counter widths were calculated such that the typical rate per counter is limited to 1-4 MHz at 10<sup>8</sup> &gamma;/sec on target.  
 
All counters will be mounted at angles such that they face normal to the path of the scattered electrons.  
 
All counters will be mounted at angles such that they face normal to the path of the scattered electrons.  
  
 
'''Scintillators'''
 
'''Scintillators'''
  
 +
<table width="100%">
 +
<tr><td width="70%">
 
{|
 
{|
 
| Material  
 
| Material  
Line 24: Line 28:
 
|!scope="row" | Counter # || width <br>[mm] || distance from <br>focal plane || E<sub>&gamma;</sub> <br>[GeV] || &Delta;E <br>[MeV]  
 
|!scope="row" | Counter # || width <br>[mm] || distance from <br>focal plane || E<sub>&gamma;</sub> <br>[GeV] || &Delta;E <br>[MeV]  
 
|-
 
|-
| 1 – 22 || 21.0 || 8 / 13 cm  || 11.43 – 11.78 || 10.2 – 23.7  
+
| 1 – 22 || 21.0 || 8 / 18 cm  || 11.43 – 11.78 || 10.2 – 23.7  
 
|-
 
|-
| 23 – 40 || 16.0 || 8 / 13 cm || 11.01 – 11.43 || 18.4 – 29.5
+
| 23 – 40 || 16.0 || 8 / 18 cm || 11.01 – 11.43 || 18.4 – 29.5
 
|-
 
|-
| 41 – 64 || 10.0 || 8 / 13 cm || 10.46 – 11.01 || 18.7 – 26.8
+
| 41 – 64 || 10.0 || 8 / 18 cm || 10.46 – 11.01 || 18.7 – 26.8
 
|-
 
|-
| 65 – 81 || 8.0 || 8 / 13 cm || 10.06 – 10.46 || 21.7 – 26.0
+
| 65 – 81 || 8.0 || 8 / 18 cm || 10.05 – 10.46 || 21.7 – 26.0
 
|-
 
|-
| 82 – 131 || 5.0 || 8 / 13 cm || 9.10 – 10.06 || 16.4 – 22.2
+
| 82 – 139 || 5.0 || 8 / 13 / 18 cm || 9.20 – 10.05 || 16.4 – 22.2
 
|-
 
|-
| 183* 207 || 4.0 || 8 / 13 cm || 7.07 – 8.08 || 16.6 – 17.2
+
| 140 195 || 4.0 || 8 / 13 / 18 cm || 7.07 – 8.13 || 16.6 – 17.2
 
|-
 
|-
| 208 – 274 || 3.0 || 8 cm || 3.05 – 7.03 || 13.7 – 20.3  
+
| 196 – 274 || 3.0 || 8 cm || 3.05 – 7.03 || 13.7 – 20.3  
 
|}
 
|}
 +
 +
</td>
 +
<td> &nbsp; &nbsp; &nbsp; [[Image:TAGH-counter-cut.jpg|100px|]]
 +
</td>
 +
</tr>
 +
</table>
  
 
'''Light guides'''
 
'''Light guides'''
Line 45: Line 55:
 
'''Photomultipliers'''
 
'''Photomultipliers'''
  
Hamamatsu R9800 1" tubes with 8 stages, magnetic shields (&mu;-metal cylinders)<br>
+
Hamamatsu R9800: 1" tube with 8 dynodes, rise time 1.0 ns, transit time 11 ns, 27% quantum eff., max. anode current 100 &mu;A.<br>
dividers and preamps developed at Jefferson Lab in order to limit the anode current<br>
+
magnetic shields: &mu;-metal cylinders.<br>
operating voltage U=900 V resulting in a gain of 5&times;10<sup>5</sup> at 4 MHz.
+
HV dividers and 2-stage preamps (amp. factor 8.5x) developed at Jefferson Lab, they allow for limiting the anode current to 15-20 &mu;A at 4 MHz rate.<br>
 +
Operating voltage: U=900 V resulting in a gain of 5&times;10<sup>5</sup>, anode current contributes to less than 5% of the active base current.
  
 
'''Readout electronics'''
 
'''Readout electronics'''
preamp boards have 2-channel output for fADC250 and F1TDC.
+
The new preamp boards have 2-channel output for fADC250 and F1TDC.
  
  
Line 56: Line 67:
 
==Fixed array counter positions==
 
==Fixed array counter positions==
  
    counter #:          consecutive counter number (in parenthesis: positions not filled for coh. edge at 9.0 GeV)
+
Table moved to [[Position and Energy Boundaries for all installed Counters]]
    coordinates:        (x<sub>center</sub>,y<sub>center</sub>) position of counter center
+
                        for z=upwards, x=along focal plane, y=towards vacuum chamber
+
    origin of coord.:  intersection of a 0.3 GeV electron ray with the focal plane
+
    angle:              entry angle of electron rays with respect to the focal plane
+
    width:              width of scintillators (in parenthesis: changed width for coh. edge at 8.0 or 7.7 GeV)
+
 
+
{| border="1" style="text-align:center;" cellpadding="10" cellspacing="0"
+
|- style="font-style:bold; color:blue;"
+
|!scope="row" | counter # || E<sub>&gamma;</sub><sup>high</sup> || E<sub>&gamma;</sub><sup>low</sup> || x<sub>center</sub> || y<sub>center</sub> || angle || width
+
|-
+
| &nbsp; || (GeV) || (GeV) || (cm) || (cm) || (deg) || (cm)
+
|-
+
| 1 || 11.78 || 11.77 || -5.858 || -13.0 || 44.078 || 2.1
+
|-
+
| 2 || 11.77 || 11.76 || -7.963 || -8.0 || 43.087 || 2.1
+
|-
+
| 3 || 11.76 || 11.749 || 0.681 || -13.0 || 42.116 || 2.1
+
|-
+
| 4 || 11.749 || 11.738 || -1.669 || -8.0 || 41.162 || 2.1
+
|-
+
| 5 || 11.738 || 11.726 || 7.474 || -13.0 || 40.237 || 2.1
+
|-
+
| 6 || 11.726 || 11.714 || 4.859 || -8.0 || 39.333 || 2.1
+
|-
+
| 7 || 11.714 || 11.701 || 14.511 || -13.0 || 38.451 || 2.1
+
|-
+
| 8 || 11.701 || 11.688 || 11.632 || -8.0 || 37.593 || 2.1
+
|-
+
| 9 || 11.688 || 11.674 || 21.812 || -13.0 || 36.755 || 2.1
+
|-
+
| 10 || 11.674 || 11.66 || 18.669 || -8.0 || 35.942 || 2.1
+
|-
+
| 11 || 11.66 || 11.645 || 29.392 || -13.0 || 35.149 || 2.1
+
|-
+
| 12 || 11.645 || 11.629 || 25.982 || -8.0 || 34.376 || 2.1
+
|-
+
| 13 || 11.629 || 11.613 || 37.264 || -13.0 || 33.623 || 2.1
+
|-
+
| 14 || 11.613 || 11.596 || 33.581 || -8.0 || 32.888 || 2.1
+
|-
+
| 15 || 11.596 || 11.578 || 45.441 || -13.0 || 32.172 || 2.1
+
|-
+
| 16 || 11.578 || 11.56 || 41.480 || -8.0 || 31.474 || 2.1
+
|-
+
| 17 || 11.56 || 11.541 || 53.938 || -13.0 || 30.793 || 2.1
+
|-
+
| 18 || 11.541 || 11.521 || 49.695 || -8.0 || 30.131 || 2.1
+
|-
+
| 19 || 11.521 || 11.5 || 62.766 || -13.0 || 29.485 || 2.1
+
|-
+
| 20 || 11.5 || 11.478 || 58.238 || -8.0 || 28.855 || 2.1
+
|-
+
| 21 || 11.478 || 11.456 || 71.945 || -13.0 || 28.242 || 2.1
+
|-
+
| 22 || 11.456 || 11.433 || 67.120 || -8.0 || 27.645 || 2.1
+
|-
+
| 23 || 11.433 || 11.414 || 80.899 || -13.0 || 27.130 || 1.6
+
|-
+
| 24 || 11.414 || 11.395 || 74.679 || -8.0 || 26.695 || 1.6
+
|-
+
| 25 || 11.395 || 11.376 || 88.400 || -13.0 || 26.269 || 1.6
+
|-
+
| 26 || 11.376 || 11.356      || 81.916 || -8.0 || 25.851 || 1.6
+
|-
+
| 27 || 11.356 || 11.335 || 96.125 || -13.0 || 25.442 || 1.6
+
|-
+
| 28 || 11.335 || 11.314 || 89.369 || -8.0 || 25.041 || 1.6
+
|-
+
| 29 || 11.314 || 11.292 || 104.077 || -13.0 || 24.648 || 1.6
+
|-
+
| 30 || 11.292 || 11.27 || 97.048 || -8.0 || 24.263 || 1.6
+
|-
+
| 31 || 11.27 || 11.247 || 112.263 || -13.0 || 23.885 || 1.6
+
|-
+
| 32 || 11.247 || 11.223 || 104.954 || -8.0 || 23.516 || 1.6
+
|-
+
| 33 || 11.223 || 11.199 || 120.688 || -13.0 || 23.153 || 1.6
+
|-
+
| 34 || 11.199 || 11.174 || 113.097 || -8.0 || 22.798 || 1.6
+
|-
+
| 35 || 11.174 || 11.148 || 129.360 || -13.0 || 22.450 || 1.6
+
|-
+
| 36 || 11.148 || 11.121 || 121.482 || -8.0 || 22.109 || 1.6
+
|-
+
| 37 || 11.121 || 11.094 || 138.282 || -13.0 || 21.775 || 1.6
+
|-
+
| 38 || 11.094 || 11.066 || 130.111 || -8.0 || 21.448 || 1.6
+
|-
+
| 39 || 11.066 || 11.038 || 147.458 || -13.0 || 21.128 || 1.6
+
|-
+
| 40 || 11.038 || 11.008 || 138.990 || -8.0 || 20.814 || 1.6
+
|-
+
| 41 || 11.008 || 10.989 || 155.994 || -13.0 || 20.563 || 1.0
+
|-
+
| 42 || 10.989 || 10.97 || 145.527 || -8.0 || 20.373 || 1.0
+
|-
+
| 43 || 10.97 || 10.951 || 162.013 || -13.0 || 20.186 || 1.0
+
|-
+
| 44 || 10.951 || 10.931 || 151.325 || -8.0 || 20.001 || 1.0
+
|-
+
| 45 || 10.931 || 10.911 || 168.137 || -13.0 || 19.818 || 1.0
+
|-
+
| 46 || 10.911 || 10.891 || 157.226 || -8.0 || 19.638 || 1.0
+
|-
+
| 47 || 10.891 || 10.87 || 174.366 || -13.0 || 19.460 || 1.0
+
|-
+
| 48 || 10.87 || 10.849 || 163.231 || -8.0 || 19.285 || 1.0
+
|-
+
| 49 || 10.849 || 10.828 || 180.703 || -13.0 || 19.111 || 1.0
+
|-
+
| 50 || 10.828 || 10.806 || 169.341 || -8.0 || 18.940 || 1.0
+
|-
+
| 51 || 10.806 || 10.784 || 187.148 || -13.0 || 18.771 || 1.0
+
|-
+
| 52 || 10.784 || 10.762 || 175.558 || -8.0 || 18.605 || 1.0
+
|-
+
| 53 || 10.762 || 10.739 || 193.702 || -13.0 || 18.441 || 1.0
+
|-
+
| 54 || 10.739 || 10.716 || 181.882 || -8.0 || 18.278 || 1.0
+
|-
+
| 55 || 10.716 || 10.692 || 200.366 || -13.0 || 18.118 || 1.0
+
|-
+
| 56 || 10.692 || 10.669 || 188.315 || -8.0 || 17.960 || 1.0
+
|-
+
| 57 || 10.669 || 10.644 || 207.143 || -13.0 || 17.803 || 1.0
+
|-
+
| 58 || 10.644 || 10.62 || 194.858 || -8.0 || 17.649 || 1.0
+
|-
+
| 59 || 10.62 || 10.595 || 214.031 || -13.0 || 17.497 || 1.0
+
|-
+
| 60 || 10.595 || 10.57 || 201.511 || -8.0 || 17.347 || 1.0
+
|-
+
| 61 || 10.57 || 10.544 || 221.033 || -13.0 || 17.199 || 1.0
+
|-
+
| 62 || 10.544 || 10.518 || 208.276 || -8.0 || 17.053 || 1.0
+
|-
+
| 63 || 10.518 || 10.492 || 228.149 || -13.0 || 16.908 || 1.0
+
|-
+
| 64 || 10.492 || 10.465 || 215.154 || -8.0 || 16.766 || 1.0
+
|-
+
| 65 || 10.465 || 10.443 || 235.015 || -13.0 || 16.639 || 0.8
+
|-
+
| 66 || 10.443 || 10.421      || 221.088 || -8.0 || 16.528 || 0.8
+
|-
+
| 67 || 10.421 || 10.399 || 240.879 || -13.0 || 16.418 || 0.8
+
|-
+
| 68 || 10.399 || 10.377 || 226.750 || -8.0 || 16.309 || 0.8
+
|-
+
| 69 || 10.377 || 10.354 || 246.817 || -13.0 || 16.201 || 0.8
+
|-
+
| 70 || 10.354 || 10.331 || 232.485 || -8.0 || 16.095 || 0.8
+
|-
+
| 71 || 10.331 || 10.308      || 252.831 || -13.0 || 15.989 || 0.8
+
|-
+
| 72 || 10.308 || 10.284 || 238.295 || -8.0 || 15.885 || 0.8
+
|-
+
| 73 || 10.284 || 10.26 || 258.919 || -13.0 || 15.781 || 0.8
+
|-
+
| 74 || 10.26 || 10.236 || 244.179 || -8.0 || 15.679 || 0.8
+
|-
+
| 75 || 10.236 || 10.212 || 265.083 || -13.0 || 15.578 || 0.8
+
|-
+
| 76 || 10.212 || 10.187 || 250.138 || -8.0 || 15.478 || 0.8
+
|-
+
| 77 || 10.187 || 10.162 || 271.324 || -13.0 || 15.379 || 0.8
+
|-
+
| 78 || 10.162 || 10.137 || 256.172 || -8.0 || 15.281 || 0.8
+
|-
+
| 79 || 10.137 || 10.112 || 277.641 || -13.0 || 15.184 || 0.8
+
|-
+
| 80 || 10.112 || 10.086 || 262.281 || -8.0 || 15.088 || 0.8
+
|-
+
| 81 || 10.086 || 10.06 || 284.034 || -13.0 || 14.993 || 0.8
+
|-
+
| 82 || 10.06 || 10.044 || 267.882 || -8.0 || 14.916 || 0.5
+
|-
+
| 83 || 10.044 || 10.027 || 288.675 || -13.0 || 14.858 || 0.5
+
|-
+
| 84 || 10.027 || 10.011 || 271.783 || -8.0 || 14.800 || 0.5
+
|-
+
| 85 || 10.011 || 9.994 || 292.745 || -13.0 || 14.742 || 0.5
+
|-
+
| 86 || 9.994 || 9.977 || 275.713 || -8.0 || 14.685 || 0.5
+
|-
+
| 87 || 9.977 || 9.96 || 296.845 || -13.0 || 14.628 || 0.5
+
|-
+
| 88 || 9.96 || 9.943 || 279.673 || -8.0 || 14.572 || 0.5
+
|-
+
| 89 || 9.943 || 9.926 || 300.975 || -13.0 || 14.516 || 0.5
+
|-
+
| 90 || 9.926 || 9.909 || 283.663 || -8.0 || 14.460 || 0.5
+
|-
+
| 91 || 9.909 || 9.892 || 305.136 || -13.0 || 14.405 || 0.5
+
|-
+
| 92 || 9.892 || 9.874 || 287.683 || -8.0 || 14.350 || 0.5
+
|-
+
| 93 || 9.874 || 9.857 || 309.327 || -13.0 || 14.295 || 0.5
+
|-
+
| 94 || 9.857 || 9.839 || 291.734 || -8.0 || 14.241 || 0.5
+
|-
+
| 95 || 9.839 || 9.821 || 313.548 || -13.0 || 14.187 || 0.5
+
|-
+
| 96 || 9.821 || 9.803 || 295.814 || -8.0 || 14.134 || 0.5
+
|-
+
| 97 || 9.803 || 9.785 || 317.800 || -13.0 || 14.081 || 0.5
+
|-
+
| 98 || 9.785 || 9.767 || 299.925 || -8.0 || 14.028 || 0.5
+
|-
+
| 99 || 9.767 || 9.749 || 322.083 || -13.0 || 13.975 || 0.5
+
|-
+
| 100 || 9.749 || 9.73 || 304.066 || -8.0 || 13.923 || 0.5
+
|-
+
| 101 || 9.73 || 9.712 || 326.396 || -13.0 || 13.871 || 0.5
+
|-
+
| 102 || 9.712 || 9.693 || 308.238 || -8.0 || 13.820 || 0.5
+
|-
+
| 103 || 9.693 || 9.674 || 330.739 || -13.0 || 13.769 || 0.5
+
|-
+
| 104 || 9.674 || 9.655 || 312.440 || -8.0 || 13.718 || 0.5
+
|-
+
| 105 || 9.655 || 9.636 || 335.114 || -13.0 || 13.668 || 0.5
+
|-
+
| 106 || 9.636 || 9.617 || 316.673 || -8.0 || 13.617 || 0.5
+
|-
+
| 107 || 9.617 || 9.598 || 339.519 || -13.0 || 13.568 || 0.5
+
|-
+
| 108 || 9.598 || 9.579 || 320.936 || -8.0 || 13.518 || 0.5
+
|-
+
| 109 || 9.579 || 9.559 || 343.955 || -13.0 || 13.469 || 0.5
+
|-
+
| 110 || 9.559 || 9.54 || 325.229 || -8.0 || 13.420 || 0.5
+
|-
+
| 111 || 9.54 || 9.52 || 348.421 || -13.0 || 13.372 || 0.5
+
|-
+
| 112 || 9.52 || 9.5 || 329.554 || -8.0 || 13.324 || 0.5
+
|-
+
| 113 || 9.5 || 9.48 || 352.918 || -13.0 || 13.276 || 0.5
+
|-
+
| 114 || 9.48 || 9.46 || 333.908 || -8.0 || 13.228 || 0.5
+
|-
+
| 115 || 9.46 || 9.44 || 357.447 || -13.0 || 13.181 || 0.5
+
|-
+
| 116 || 9.44 || 9.42 || 338.294 || -8.0 || 13.134 || 0.5
+
|-
+
| 117 || 9.42 || 9.399 || 362.005 || -13.0 || 13.088 || 0.5
+
|-
+
| 118 || 9.399 || 9.379 || 342.711 || -8.0 || 13.041 || 0.5
+
|-
+
| 119 || 9.379 || 9.358 || 366.595 || -13.0 || 12.996 || 0.5
+
|-
+
| 120 || 9.358 || 9.337 || 347.158 || -8.0 || 12.950 || 0.5
+
|-
+
| 121 || 9.337 || 9.316 || 371.216 || -13.0 || 12.904 || 0.5
+
|-
+
| 122 || 9.316 || 9.295 || 351.636 || -8.0 || 12.859 || 0.5
+
|-
+
| 123 || 9.295 || 9.274 || 375.868 || -13.0 || 12.815 || 0.5
+
|-
+
| 124 || 9.274 || 9.253 || 356.145 || -8.0 || 12.770 || 0.5
+
|-
+
| 125 || 9.253 || 9.231 || 380.551 || -13.0 || 12.726 || 0.5
+
|-
+
| 126 || 9.231 || 9.21 || 360.685 || -8.0 || 12.682 || 0.5
+
|-
+
| 127 || 9.21 || 9.188 || 385.264 || -13.0 || 12.639 || 0.5
+
|-
+
| 128 || 9.188 || 9.166 || 365.255 || -8.0 || 12.595 || 0.5
+
|-
+
| 129 || 9.166 || 9.144 || 390.009 || -13.0 || 12.552 || 0.5
+
|-
+
| 130 || 9.144 || 9.122 || 369.857 || -8.0 || 12.509 || 0.5
+
|-
+
| 131 || 9.122 || 9.1 || 394.784 || -13.0 || 12.467 || 0.5
+
|- style="color:grey;"
+
!scope="row" | (132) || 9.1 || 9.078 || 374.489 || -8.0 || 12.425 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (133) || 9.078 || 9.055 || 399.591 || -13.0 || 12.383 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (134) || 9.055 || 9.033 || 379.153 || -8.0 || 12.341 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (135) || 9.033 || 9.01 || 404.428 || -13.0 || 12.300 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (136) || 9.01 || 8.987 || 383.847 || -8.0 || 12.259 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (137) || 8.987 || 8.964 || 409.297 || -13.0 || 12.218 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (138) || 8.964 || 8.941 || 388.573 || -8.0 || 12.178 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (139) || 8.941 || 8.918 || 414.196 || -13.0 || 12.137 || (0.5)
+
|- style="color:grey;"
+
!scope="row" | (140) || 8.918 || 8.899 || 439.731 || -18.0 || 12.101 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (141) || 8.899 || 8.881 || 395.001 || -8.0 || 12.069 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (142) || 8.881 || 8.862 || 420.364 || -13.0 || 12.038 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (143) || 8.862 || 8.843 || 445.858 || -18.0 || 12.006 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (144) || 8.843 || 8.824 || 400.762 || -8.0 || 11.975 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (145) || 8.824 || 8.805 || 426.330 || -13.0 || 11.944 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (146) || 8.805 || 8.786 || 452.030 || -18.0 || 11.913 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (147) || 8.786 || 8.766 || 406.569 || -8.0 || 11.882 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (148) || 8.766 || 8.747 || 432.341 || -13.0 || 11.851 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (149) || 8.747 || 8.728 || 458.245 || -18.0 || 11.821 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (150) || 8.728 || 8.708 || 412.420 || -8.0 || 11.790 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (151) || 8.708 || 8.689 || 438.397 || -13.0 || 11.760 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (152) || 8.689 || 8.669 || 464.506 || -18.0 || 11.730 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (153) || 8.669 || 8.649 || 418.315 || -8.0 || 11.700 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (154) || 8.649 || 8.629 || 444.497 || -13.0 || 11.671 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (155) || 8.629 || 8.609 || 470.810 || -18.0 || 11.641 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (156) || 8.609 || 8.589 || 424.255 || -8.0 || 11.612 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (157) || 8.589 || 8.569 || 450.641 || -13.0 || 11.582 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (158) || 8.569 || 8.549 || 477.159 || -18.0 || 11.553 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (159) || 8.549 || 8.529 || 430.239 || -8.0 || 11.524 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (160) || 8.529 || 8.509 || 456.830 || -13.0 || 11.496 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (161) || 8.509 || 8.488 || 483.551 || -18.0 || 11.467 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (162) || 8.488 || 8.468 || 436.268 || -8.0 || 11.438 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (163) || 8.468 || 8.447 || 463.063 || -13.0 || 11.410 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (164) || 8.447 || 8.427 || 489.988 || -18.0 || 11.382 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (165) || 8.427 || 8.406 || 442.342 || -8.0 || 11.354 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (166) || 8.406 || 8.385 || 469.340 || -13.0 || 11.326 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (167) || 8.385 || 8.364 || 496.469 || -18.0 || 11.298 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (168) || 8.364 || 8.343 || 448.460 || -8.0 || 11.271 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (169) || 8.343 || 8.322 || 475.661 || -13.0 || 11.243 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (170) || 8.322 || 8.301 || 502.993 || -18.0 || 11.216 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (171) || 8.301 || 8.279 || 454.622 || -8.0 || 11.189 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (172) || 8.279 || 8.258 || 482.027 || -13.0 || 11.162 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (173) || 8.258 || 8.237 || 509.561 || -18.0 || 11.135 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (174) || 8.237 || 8.215 || 460.829 || -8.0 || 11.108 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (175) || 8.215 || 8.194 || 488.436 || -13.0 || 11.082 || (0.4)
+
|- style="color:grey;"
+
!scope="row" | (176) || 8.194 || 8.177 || 515.897 || -18.0 || 11.058 || (0.3)
+
|- style="color:grey;"
+
!scope="row" | (177) || 8.177 || 8.161 || 466.296 || -8.0 || 11.039 || (0.3)
+
|- style="color:grey;"
+
!scope="row" | (178) || 8.161 || 8.145 || 493.541 || -13.0 || 11.019 || (0.3)
+
|- style="color:grey;"
+
!scope="row" | (179) || 8.145 || 8.128 || 520.883 || -18.0 || 10.999 || (0.3)
+
|- style="color:grey;"
+
!scope="row" | (180) || 8.128 || 8.112 || 471.009 || -8.0 || 10.980 || (0.3)
+
|- style="color:grey;"
+
!scope="row" | (181) || 8.112 || 8.095 || 498.403 || -13.0 || 10.960 || (0.3)
+
|- style="color:grey;"
+
!scope="row" | (182) || 8.095 || 8.079 || 525.894 || -18.0 || 10.941 || (0.3)
+
|-
+
| 183 || 8.079 || 8.062 || 475.746 || -8.0 || 10.922 || 0.4 (0.3)
+
|- style="color:grey;"
+
!scope="row" | (184) || 8.062 || 8.045 || 503.290 || -13.0 || 10.903 ||(0.3)
+
|-
+
| 185 || 8.045 || 8.029 || 504.924 <br> (530.929) || -13.0 <br> (-18.0) || 10.883 || 0.4 (0.3)
+
|- style="color:grey;"
+
!scope="row" | (186) || 8.029 || 8.012 || 480.509 || -8.0 || 10.864 || (0.3)
+
|-
+
| 187 || 8.012 || 7.995 || 482.102 <br> (508.201) || -8.0 <br> (-13.0) || 10.845 || 0.4 (0.3)
+
|- style="color:grey;"
+
!scope="row" | (188) || 7.995 || 7.978 || 535.988 || -18.0 || 10.827 || (0.3)
+
|-
+
| 189 || 7.978 || 7.961 || 511.488 <br> (485.297) || -13.0 <br> (-8.0) || 10.808 || 0.4 (0.3)
+
|- style="color:grey;"
+
!scope="row" | (190) || 7.961 || 7.944 || 513.136 || -13.0 || 10.789 || (0.3)
+
|-
+
| 191 || 7.944 || 7.927 || 488.502 <br> (541.072) || -8.0 <br> (-18.0) || 10.770 || 0.4 (0.3)
+
|- style="color:grey;"
+
!scope="row" | (192) || 7.927 || 7.91 || 490.109 || -8.0 || 10.752 || (0.3)
+
|-
+
| 193 || 7.91 || 7.893 || 518.096 || -13.0 || 10.733   || 0.4 (0.3)
+
|-
+
| 194 || 7.869 || 7.851 || 495.67 || -8.0 || 10.679 || 0.4 (0.3)
+
|-
+
| 195 || 7.809 || 7.791 || 501.30 || -8.0 || 10.616 || 0.4 (0.3)
+
|-
+
| 196 || 7.749 || 7.731 || 506.90 || -8.0 || 10.555 || 0.4 (0.3)
+
|-
+
| 197 || 7.689 || 7.671 || 512.49 || -8.0 || 10.495 || 0.4 (0.3)
+
|-
+
| 198 || 7.629 || 7.611 || 518.06 || -8.0 || 10.436 || 0.4 (0.3)
+
|-
+
| 199 || 7.569 || 7.551 || 523.60 || -8.0 || 10.378 || 0.4 (0.3)
+
|-
+
| 200 || 7.509 || 7.491 || 529.13 || -8.0 || 10.322 || 0.4 (0.3)
+
|-
+
| 201 || 7.449 || 7.431 || 534.63 || -8.0 || 10.267 || 0.4 (0.3)
+
|-
+
| 202 || 7.389 || 7.371 || 540.12 || -8.0 || 10.214 || 0.4 (0.3)
+
|-
+
| 203 || 7.329 || 7.311 || 545.59 || -8.0 || 10.161 || 0.4 (0.3)
+
|-
+
| 204 || 7.269 || 7.251 || 551.04 || -8.0 || 10.109 || 0.4 (0.3)
+
|-
+
| 205 || 7.209 || 7.190 || 556.47 || -8.0 || 10.059 || 0.4 (0.3)
+
|-
+
| 206 || 7.150 || 7.130 || 561.88 || -8.0 || 10.010 || 0.4 (0.3)
+
|-
+
| 207 || 7.090 || 7.070 || 567.28 || -8.0 || 9.961 || 0.4 (0.3)
+
|-
+
| 208 || 7.030 || 7.010 || 572.66 || -8.0 || 9.914 || 0.3
+
|-
+
| 209 || 6.970 || 6.950 || 578.02 || -8.0 || 9.867 || 0.3
+
|-
+
| 210 || 6.910 || 6.890 || 583.37 || -8.0 || 9.822 || 0.3
+
|-
+
| 211 || 6.850 || 6.830 || 588.70 || -8.0 || 9.777 || 0.3
+
|-
+
| 212 || 6.790 || 6.770 || 594.01 || -8.0 || 9.733 || 0.3
+
|-
+
| 213 || 6.730 || 6.710 || 599.31 || -8.0 || 9.690 || 0.3
+
|-
+
| 214 || 6.670 || 6.650 || 604.60 || -8.0 || 9.648 || 0.3
+
|-
+
| 215 || 6.610 || 6.590 || 609.87 || -8.0 || 9.607 || 0.3
+
|-
+
| 216 || 6.550 || 6.530 || 615.12 || -8.0 || 9.566 || 0.3
+
|-
+
| 217 || 6.490 || 6.470 || 620.37 || -8.0 || 9.526 || 0.3
+
|-
+
| 218 || 6.430 || 6.410 || 625.59 || -8.0 || 9.487 || 0.3
+
|-
+
| 219 || 6.371 || 6.349 || 630.81 || -8.0 || 9.449 || 0.3
+
|-
+
| 220 || 6.311 || 6.289 || 636.01 || -8.0 || 9.411 || 0.3
+
|-
+
| 221 || 6.251 || 6.229 || 641.20 || -8.0 || 9.374 || 0.3
+
|-
+
| 222 || 6.191 || 6.169 || 646.38 || -8.0 || 9.337 || 0.3
+
|-
+
| 223 || 6.131 || 6.109 || 651.54 || -8.0 || 9.301 || 0.3
+
|-
+
| 224 || 6.071 || 6.049 || 656.69 || -8.0 || 9.266 || 0.3
+
|-
+
| 225 || 6.011 || 5.989 || 661.83 || -8.0 || 9.231 || 0.3
+
|-
+
| 226 || 5.951 || 5.929 || 666.96 || -8.0 || 9.197 || 0.3
+
|-
+
| 227 || 5.891 || 5.869 || 672.08 || -8.0 || 9.163 || 0.3
+
|-
+
| 228 || 5.831 || 5.809 || 677.18 || -8.0 || 9.130 || 0.3
+
|-
+
| 229 || 5.771 || 5.749 || 682.27 || -8.0 || 9.098 || 0.3
+
|-
+
| 230 || 5.711 || 5.689 || 687.36 || -8.0 || 9.066 || 0.3
+
|-
+
| 231 || 5.651 || 5.629 || 692.43 || -8.0 || 9.034 || 0.3
+
|-
+
| 232 || 5.591 || 5.569 || 697.49 || -8.0 || 9.003 || 0.3
+
|-
+
| 233 || 5.531 || 5.509 || 702.55 || -8.0 || 8.973 || 0.3
+
|-
+
| 234 || 5.471 || 5.449 || 707.59 || -8.0 || 8.943 || 0.3
+
|-
+
| 235 || 5.412 || 5.388 || 712.62 || -8.0 || 8.913 || 0.3
+
|-
+
| 236 || 5.352 || 5.328 || 717.64 || -8.0 || 8.884 || 0.3
+
|-
+
| 237 || 5.292 || 5.268 || 722.66 || -8.0 || 8.855 || 0.3
+
|-
+
| 238 || 5.232 || 5.208 || 727.66 || -8.0 || 8.826 || 0.3
+
|-
+
| 239 || 5.172 || 5.148 || 732.66 || -8.0 || 8.798 || 0.3
+
|-
+
| 240 || 5.112 || 5.088 || 737.64 || -8.0 || 8.771 || 0.3
+
|-
+
| 241 || 5.052 || 5.028 || 742.62 || -8.0 || 8.743 || 0.3
+
|-
+
| 242 || 4.992 || 4.968 || 747.59 || -8.0 || 8.716 || 0.3
+
|-
+
| 243 || 4.932 || 4.908 || 752.55 || -8.0 || 8.690 || 0.3
+
|-
+
| 244 || 4.872 || 4.848 || 757.50 || -8.0 || 8.664 || 0.3
+
|-
+
| 245 || 4.812 || 4.788 || 762.45 || -8.0 || 8.638 || 0.3
+
|-
+
| 246 || 4.752 || 4.728 || 767.38 || -8.0 || 8.612 || 0.3
+
|-
+
| 247 || 4.692 || 4.668 || 772.31 || -8.0 || 8.587 || 0.3
+
|-
+
| 248 || 4.632 || 4.608 || 777.23 || -8.0 || 8.562 || 0.3
+
|-
+
| 249 || 4.572 || 4.548 || 782.15 || -8.0 || 8.537 || 0.3
+
|-
+
| 250 || 4.512 || 4.488 || 787.06 || -8.0 || 8.513 || 0.3
+
|-
+
| 251 || 4.452 || 4.428 || 791.97 || -8.0 || 8.488 || 0.3
+
|-
+
| 252 || 4.392 || 4.368 || 796.87 || -8.0 || 8.464 || 0.3
+
|-
+
| 253 || 4.333 || 4.307 || 801.76 || -8.0 || 8.441 || 0.3
+
|-
+
| 254 || 4.273 || 4.247 || 806.65 || -8.0 || 8.417 || 0.3
+
|-
+
| 255 || 4.213 || 4.187 || 811.53 || -8.0 || 8.394 || 0.3
+
|-
+
| 256 || 4.153 || 4.127 || 816.41 || -8.0 || 8.371 || 0.3
+
|-
+
| 257 || 4.093 || 4.067 || 821.28 || -8.0 || 8.348 || 0.3
+
|-
+
| 258 || 4.033 || 4.007 || 826.15 || -8.0 || 8.326 || 0.3
+
|-
+
| 259 || 3.973 || 3.947 || 831.02 || -8.0 || 8.303 || 0.3
+
|-
+
| 260 || 3.913 || 3.887 || 835.88 || -8.0 || 8.281 || 0.3
+
|-
+
| 261 || 3.853 || 3.827 || 840.75 || -8.0 || 8.259 || 0.3
+
|-
+
| 262 || 3.793 || 3.767 || 845.61 || -8.0 || 8.237 || 0.3
+
|-
+
| 263 || 3.733 || 3.707 || 850.47 || -8.0 || 8.216 || 0.3
+
|-
+
| 264 || 3.673 || 3.647 || 855.34 || -8.0 || 8.194 || 0.3
+
|-
+
| 265 || 3.613 || 3.587 || 860.21 || -8.0 || 8.173 || 0.3
+
|-
+
| 266 || 3.553 || 3.527 || 865.08 || -8.0 || 8.152 || 0.3
+
|-
+
| 267 || 3.493 || 3.467 || 869.95 || -8.0 || 8.131 || 0.3
+
|-
+
| 268 || 3.433 || 3.407 || 874.83 || -8.0 || 8.110 || 0.3
+
|-
+
| 269 || 3.373 || 3.347 || 879.71 || -8.0 || 8.089 || 0.3
+
|-
+
| 270 || 3.313 || 3.287 || 884.59 || -8.0 || 8.068 || 0.3
+
|-
+
| 271 || 3.253 || 3.227 || 889.49 || -8.0 || 8.047 || 0.3
+
|-
+
| 272 || 3.193 || 3.167 || 894.39 || -8.0 || 8.027 || 0.3
+
|-
+
| 273 || 3.133 || 3.107 || 899.29 || -8.0 || 8.006 || 0.3
+
|-
+
| 274 || 3.073 || 3.047 || 904.21 || -8.0 || 7.986 || 0.3
+
|}
+

Latest revision as of 20:00, 25 January 2017

TAGH-from-magnet-all.jpg

In its standard configuration the fixed-array hodoscope consists of 218 scintillators distributed over 9.1 m behind the focal-plane of the tagger spectrometer. Standard configuration refers to a coherent-peak setting at 9.0 GeV, i.e. the microscope covers the energy range 8.1<Eγ<9.1 GeV.

Tagging range (for a 12 GeV electron beam):

  • Photons between 3.0 GeV and 8.2 GeV: detector positions correspond to 60 MeV steps in Eγ with 30-50% sampling. The counter widths are chosen such that the typical rate per counter is limited to 3-4 MHz at 108 γ/sec on target;
  • Photons between 9.2 GeV and 11.78 GeV: scintillators cover the full energy range, counter widths were calculated such that the typical rate per counter is limited to 1-4 MHz at 108 γ/sec on target.

All counters will be mounted at angles such that they face normal to the path of the scattered electrons.

Scintillators

Material EJ-228
Thickness     6 mm
Height 40 mm (slotted into the light guides, slot depth: 3mm)


Counter # width
[mm]
distance from
focal plane
Eγ
[GeV]
ΔE
[MeV]
1 – 22 21.0 8 / 18 cm 11.43 – 11.78 10.2 – 23.7
23 – 40 16.0 8 / 18 cm 11.01 – 11.43 18.4 – 29.5
41 – 64 10.0 8 / 18 cm 10.46 – 11.01 18.7 – 26.8
65 – 81 8.0 8 / 18 cm 10.05 – 10.46 21.7 – 26.0
82 – 139 5.0 8 / 13 / 18 cm 9.20 – 10.05 16.4 – 22.2
140 – 195 4.0 8 / 13 / 18 cm 7.07 – 8.13 16.6 – 17.2
196 – 274 3.0 8 cm 3.05 – 7.03 13.7 – 20.3
      TAGH-counter-cut.jpg

Light guides

All light guides (UVT PMMA) have cylindrical shape of 120 mm length and 7/8" = 22.2mm diameter to cover the size of the photocathode. A collar at 60mm height with 2 bolts along the slot line ensure proper positioning of the counters: threaded holes for the bolts in the mounting plates are correspondingly oriented.

Photomultipliers

Hamamatsu R9800: 1" tube with 8 dynodes, rise time 1.0 ns, transit time 11 ns, 27% quantum eff., max. anode current 100 μA.
magnetic shields: μ-metal cylinders.
HV dividers and 2-stage preamps (amp. factor 8.5x) developed at Jefferson Lab, they allow for limiting the anode current to 15-20 μA at 4 MHz rate.
Operating voltage: U=900 V resulting in a gain of 5×105, anode current contributes to less than 5% of the active base current.

Readout electronics The new preamp boards have 2-channel output for fADC250 and F1TDC.


Fixed array counter positions

Table moved to Position and Energy Boundaries for all installed Counters