Adjusting the transfer line laser height to reflect something closer to the average of the actual readings in the ME+4 DCOPS sensors gives a slightly different set of fits. The "chi-squared" for this system (which has 24 DCOPS and 2617 different parameters) is 2594. The component of this from measured quantities is only 76.
| Type | YE+1-YE+3 | YE+2-YE+3 | YE+1-YE+3 | YE+2-YE+3 | YE+1-YE+3 | YE+2-YE+3 |
| PG | PG | hand | hand | Cocoa | Cocoa | |
| X (mm) | -.01 | -.74 | -1.03 | -1.08 | 0.61 | 0.43 |
| Y (mm) | -1.33 | 0.61 | 1.28 | 2.07 | -0.76 | -1.21 |
| φ z (mrad) | -0.61 | -0.64 | -0.98 | -0.86 | -0.72 | -0.76 |
The disk rotations found by Cocoa are consistent with survey results, which claim a 0.1 mrad error.
The disk position numbers are not consistent with survey results, which claim a 0.3mm error.
I have no transfer point lasers to study, so I cannot estimate how much or in what direction distortion will change the relative positions. However, it seems logical that distortions at ME+4, while they may change the positions of YE+1 and YE+2 relative to YE+3, should not radically change the relative positions of YE+1 and YE+2.
If I open up the X/Y error on disk positions from 0.5mm to 2mm (much more realistic), the fit results change as shown in the table below. The new "chi-squared" is 2581, with 77 of that coming from the 96 measured quantities.
| Type | YE+1-YE+3 | YE+2-YE+3 | YE+1-YE+3 | YE+2-YE+3 | YE+1-YE+3 | YE+2-YE+3 |
| PG | PG | hand | hand | Cocoa | Cocoa | |
| X (mm) | -.01 | -.74 | -1.03 | -1.08 | 0.97 | 0.59 |
| Y (mm) | -1.33 | 0.61 | 1.28 | 2.07 | -1.22 | -1.51 |
| φ z (mrad) | -0.61 | -0.64 | -0.98 | -0.86 | -0.73 | -0.76 |
For field-on I get slightly different results. Obviously the survey is no longer relevant, and I haven't redone the hand calculation yet.
| Type | YE+1-YE+3 | YE+2-YE+3 | YE+1 on-off | YE+2 on-off |
| Cocoa | Cocoa | |||
| X (mm) | 0.40 | -0.86 | -0.57 | -1.45 |
| Y (mm) | -0.06 | -1.32 | 1.16 | 0.19 |
| φ z (mrad) | -0.56 | -0.66 | 0.17 | 0.10 |
The transfer plate positions follow. Note that these are not absolute positions; they are fit relative to YE+3. The coordinates are CMS coordinates, but a shift or rotation of YE+3 will change these.
| Position | Off X | Off Y | Off Z | On X | On Y | On Z | On-Off X | On-Off Y | On-Off Z |
| ME+1_tp1 | 6912.9421 | 1935.1675 | 6830.7836 | 6913.5721 | 1937.3148 | 6830.4823 | 0.63 | 2.1473 | -0.3013 |
| ME+1_tp2 | 1779.7329 | 6954.9784 | 6828.0205 | 1777.8358 | 6956.998 | 6827.7132 | -1.8971 | 2.0196 | -0.3073 |
| ME+1_tp3 | -5040.2847 | 5106.8982 | 6829.8196 | -5042.8433 | 5108.2352 | 6829.5094 | -2.5586 | 1.337 | -0.3102 |
| ME+1_tp4 | -6942.5818 | -1813.2842 | 6832.3267 | -6943.7461 | -1814.4703 | 6832.0219 | -1.1643 | -1.1861 | -0.3048 |
| ME+1_tp5 | -1775.8844 | -6955.4765 | 6825.484 | -1775.2888 | -6957.3114 | 6825.1912 | 0.5956 | -1.8349 | -0.2928 |
| ME+1_tp6 | 5132.7085 | -5016.2129 | 6829.6667 | 5133.9749 | -5016.7247 | 6829.3769 | 1.2664 | -0.5118 | -0.2898 |
| ME+2_tp1 | 6851.1941 | 2162.9339 | 8046.9626 | 6849.835 | 2163.703 | 8046.2849 | -1.3591 | 0.7691 | -0.6777 |
| ME+2_tp4 | -7004.1327 | -1586.5708 | 8046.8814 | -7004.5801 | -1587.2206 | 8049.4415 | -0.4474 | -0.6498 | 2.5601 |
| ME+2_tp2 | 2132.9745 | 6857.1608 | 8048.8301 | 2129.5137 | 6857.6326 | 8049.5451 | -3.4608 | 0.4718 | 0.715 |
| ME+2_tp5 | -1550.5692 | -7014.8647 | 8049.2323 | -1550.3002 | -7014.5777 | 8050.1834 | 0.269 | 0.287 | 0.9511 |
| ME+2_tp3 | -5298.6248 | 4847.8608 | 8048.1294 | -5299.5747 | 4847.253 | 8050.5771 | -0.9499 | -0.6078 | 2.4477 |
| ME+2_tp6 | 4874.8967 | -5275.0774 | 8049.4417 | 4874.605 | -5273.7046 | 8048.8908 | -0.2917 | 1.3728 | -0.5509 |
| ME+3_tp1 | 6862.9871 | 2118.7407 | 9593.8594 | 6863.3852 | 2119.1636 | 9593.1747 | 0.3981 | 0.4229 | -0.6847 |
| ME+3_tp4 | -7015.6702 | -1541.6022 | 9594.5957 | -7016.6316 | -1542.0515 | 9597.1572 | -0.9614 | -0.4493 | 2.5615 |
| ME+3_tp2 | 2174.0534 | 6845.6552 | 9595.3465 | 2174.3231 | 6846.7566 | 9596.0484 | 0.2697 | 1.1014 | 0.7019 |
| ME+3_tp5 | -1553.1524 | -6844.5668 | 9592.0421 | -1553.1509 | -6844.9782 | 9592.9972 | 0.0015 | -0.4114 | 0.9551 |
| ME+3_tp3 | -5265.0842 | 4879.5114 | 9594.7714 | -5266.696 | 4879.9704 | 9597.2237 | -1.6118 | 0.459 | 2.4523 |
| ME+3_tp6 | 4842.7046 | -5307.513 | 9595.6045 | 4843.0888 | -5308.0357 | 9595.0571 | 0.3842 | -0.5227 | -0.5474 |
| ME+4_tp1 | 6862.4196 | 2122.957 | 10489.231 | 6861.58 | 2123.2549 | 10489.231 | -0.8396 | 0.2979 | 0 |
| ME+4_tp4 | -7014.6637 | -1547.8374 | 10488.84 | -7014.1873 | -1547.5874 | 10488.841 | 0.4764 | 0.25 | 0.001 |
| ME+4_tp2 | 2168.0668 | 6848.645 | 10493.34 | 2169.0731 | 6847.6277 | 10493.34 | 1.0063 | -1.0173 | 0 |
| ME+4_tp5 | -1587.3379 | -7002.8201 | 10493.279 | -1587.9661 | -7002.3415 | 10493.28 | -0.6282 | 0.4786 | 0.001 |
| ME+4_tp3 | -5272.0546 | 4877.0211 | 10492.404 | -5271.9518 | 4876.0248 | 10492.398 | 0.1028 | -0.9963 | -0.006 |
| ME+4_tp6 | 4844.9719 | -5302.4337 | 10490.849 | 4844.8816 | -5301.4593 | 10490.851 | -0.0903 | 0.9744 | 0.002 |
The transfer point shifts are graphically shown below. Units are mm. I ignore Z, since we have poor sensitivity to it. We expect stations ME+2 and ME+3 to be similar. They are shown by green and blue arrows respectively.
Modified 07-May-2009 at 08:58
http://hep.physics.wisc.edu/~jnb/cms/07May2009
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