1. University of Wisconsin-Madison
DCOPS Update
James N. Bellinger
University of Wisconsin-Madison
13-October-2009
James N. Bellinger 13-October-2009

2. External Validation
PG exists for pre-field endcap disks PG exists for 8 transfer plates after CRAFT As of Monday night, no other relevant PG is available. The 8 transfer plates are supposed to be ready in CMS space later this week Recalculating the transfer plate positions gives tighter fit vs PG spreads
James N. Bellinger 13-October-2009

3. Internal Validation of Z
Z studies based on drawings and MAB fits strongly suggest that something is amiss in the Plus Endcap at transfer line 5. Omit this and estimate the endcap rotations using only un-PG-corrected transfer plate Z estimates (comparison shown later)
James N. Bellinger 13-October-2009

4. Internal Validation of X/Y
Consider the slice through the detector along the SLM2/Z plane Motion of the disks along the SLM line will appear in the L/R DCOPS measurements, in opposite directions on each side Lasers from each side should give the same pattern of center deviations from a line drawn from ME+4 center to ME-4 center PG measurements of TP positions should do the same, but with opposite sign
James N. Bellinger 13-October-2009

5. Example TP 1 and 4 Animated GIF Will not display in PDF Laser diffs
(black) agree well
with each other
within a single line
Cocoa fit includes other
constraints
No PG for MAB
Large excursions in central region
James N. Bellinger 13-October-2009

6. Internal vs External
Combining before and after PG (unwarranted and inaccurate) gives me deviations from the internal estimates of 4 transfer plates: 11.5, 3.4, 13.3 and 4.8mm Rotation estimates from Z are not fully consistent with (inappropriate) PG
rotX fit (mrad)
rotY fit (mrad)
OLD PG rotX
OLD PG rotY
YE+1
-0.44
-0.07
-0.26
-0.23
YE+2/ME2
-0.60
0.10
0.23
-0.13
YE+2/ME3
-0.55
-0.08
YE+3
-0.73
-0.21
-0.54
-0.24
James N. Bellinger 13-October-2009

7. Pre-CRAFT Hack
I used the CMS-SG-UR-0140 pre-CRAFT survey numbers in a Plus Endcap model together with my Transfer Plate PG numbers I don’t have Link data for this period I did not attempt to predict what the positions would be after the disks pulled together
James N. Bellinger 13-October-2009

8. Example results: ME+1/3 Center Z (mm) Floating/fixed
Tilt (in-out) (mrad)
ME+1/3/03 /
2.19
ME+1/3/09 /
3.53
ME+1/3/14 /
3.43
ME+1/3/20 /
0.24
ME+1/3/27 /
6.60
ME+1/3/33 /
4.13
Dubious about slopes here: need better Link coordination!

9. Conclusions?
Correcting Dave’s PG numbers for the relative positions of the transfer plates helps noticeably.
I still have nothing to compare Z estimates from the Z-sensors to, or PG useful for aligning the SLMs. All we have is pre field- on. It could use some tweaking.
Numbers for ME4 are supposed to be ready this week
James N. Bellinger 13-October-2009

10. BACKUP
“I've been working for five days without any sleep to finish this report. At first I had a mental block. But on the fourth day I was visited by an Incan monkey god who told me what to write. Now I just have to find somebody who can translate his simple but beautiful language.” Scott Adams
James N. Bellinger 13-October-2009