Line 142: |
Line 142: |
| ===<u>A summary of the spreadsheet calculations is a follows:</u>=== | | ===<u>A summary of the spreadsheet calculations is a follows:</u>=== |
| [[Image:Bundle_support_displacement.jpg|right|thumb|475px|Figure 16: Sketch showing the X-displacement along the focal plane (Δx) from the center of the first fiber column to the center of the sixth fiber column of the first bundle support.]] | | [[Image:Bundle_support_displacement.jpg|right|thumb|475px|Figure 16: Sketch showing the X-displacement along the focal plane (Δx) from the center of the first fiber column to the center of the sixth fiber column of the first bundle support.]] |
− |
| |
| | | |
| <ul> | | <ul> |
− | <li>Select a starting energy for the photon tagging array (highest γ energy to tag)</li> | + | <li style="padding-bottom: 16px;">Select a starting energy for the photon tagging array (highest γ energy to tag)</li> |
| <li>Using [https://halldweb.jlab.org/wiki/images/b/b6/Counterbounds2017%28b%29.xlsx hodoscope energy bin bounds] interpolate the crossing angle with respect to the focal plane (β<sub>1</sub>) of an electron associated the highest energy to be tagged (E<sub>γ<sub>o</sub></sub>)</li> | | <li>Using [https://halldweb.jlab.org/wiki/images/b/b6/Counterbounds2017%28b%29.xlsx hodoscope energy bin bounds] interpolate the crossing angle with respect to the focal plane (β<sub>1</sub>) of an electron associated the highest energy to be tagged (E<sub>γ<sub>o</sub></sub>)</li> |
| <ul> | | <ul> |
| <li> Interpolate the location on the X<sub>FP</sub> axis at which this electron crosses (X<sub>1</sub>)</li> | | <li> Interpolate the location on the X<sub>FP</sub> axis at which this electron crosses (X<sub>1</sub>)</li> |
− | <li> These electrons will pass through the center of the first column of SciFi fibers</li> | + | <li style="padding-bottom: 16px;"> These electrons will pass through the center of the first column of SciFi fibers</li> |
| </ul> | | </ul> |
| | | |
Line 209: |
Line 208: |
| <li>Use the difference between β<sub>avg</sub> and 19.5072<sup>o</sup></li> | | <li>Use the difference between β<sub>avg</sub> and 19.5072<sup>o</sup></li> |
| <li>The distance of the center of the first fiber column's front face to the bundle support's pivot point (in the (x, y)<sub>FP</sub> plane) is 0.5895 inches</li> | | <li>The distance of the center of the first fiber column's front face to the bundle support's pivot point (in the (x, y)<sub>FP</sub> plane) is 0.5895 inches</li> |
− | <li>Note that if β > ~19.5<sup>o</sup> (e.g. > 10.86 GeV photons being tagged), then the pivot point will be below the focal plane; therefore, Δy will be positive (bundle shifts towards the magnet, positive Y<sub>FP</sub> direction)</li> | + | <li style="padding-bottom: 16px;">Note that if β > ~19.5<sup>o</sup> (e.g. > 10.86 GeV photons being tagged), then the pivot point will be below the focal plane; therefore, Δy will be positive (bundle shifts towards the magnet, positive Y<sub>FP</sub> direction)</li> |
| </ul> | | </ul> |
− | <li>Utilizing the y-displacement value found above and the tangent of β<sub>avg</sub>, calculate the associated x-displacement along the focal plane to keep column #1 aligned to the electrons associated with E<sub>γ<sub>o</sub></sub></li> | + | <li style="padding-bottom: 16px;">Utilizing the y-displacement value found above and the tangent of β<sub>avg</sub>, calculate the associated x-displacement along the focal plane to keep column #1 aligned to the electrons associated with E<sub>γ<sub>o</sub></sub></li> |
| <li>Next determine the locations of the bundle support mounting rods in focal plane coordinates</li> | | <li>Next determine the locations of the bundle support mounting rods in focal plane coordinates</li> |
| <ul> | | <ul> |
Line 226: |
Line 225: |
| <b><center>Since the post-bremsstrahlung electron's crossing angle changes with energy (e.g. displacement along the focal plane) each bundle support will have a slight "kick" or "tow" from the adjacent bundle support.</center> | | <b><center>Since the post-bremsstrahlung electron's crossing angle changes with energy (e.g. displacement along the focal plane) each bundle support will have a slight "kick" or "tow" from the adjacent bundle support.</center> |
| <center>Simply put, going from upstream [highest E<sub>γ</sub>] to downstream [lowest E<sub>γ</sub>], subsequent bundle supports will have smaller and smaller β<sub>avg</sub>'s.</center></b> | | <center>Simply put, going from upstream [highest E<sub>γ</sub>] to downstream [lowest E<sub>γ</sub>], subsequent bundle supports will have smaller and smaller β<sub>avg</sub>'s.</center></b> |
− | <li></li> | + | <li style="padding-bottom: 16px;"></li> |
− | <li></li> | + | <li style="padding-bottom: 16px;"></li> |
| | | |
| </ul> | | </ul> |
| + | |
| + | |
| + | |
| + | |
| + | |
| + | [[Image:Tow_Move.png|center|thumb|400px|Figure 12: CAD image of a bundle support (blue) with a mounted 5x6 fiber bundle. The 'S' bend minimizes the amount of fiber in the path of the electrons.]] |
| + | |
| + | |
| + | |
| + | [[Image:Tow2.png|center|thumb|400px|Figure 12: CAD image of a bundle support (blue) with a mounted 5x6 fiber bundle. The 'S' bend minimizes the amount of fiber in the path of the electrons.]] |
| + | |
| + | |
| + | |
| + | [[Image:Tow3.png|center|thumb|400px|Figure 12: CAD image of a bundle support (blue) with a mounted 5x6 fiber bundle. The 'S' bend minimizes the amount of fiber in the path of the electrons.]] |
| | | |
| | | |