1. University of Wisconsin-Madison
Transfer Lines
James N. Bellinger
University of Wisconsin-Madison
20-June-2009
James N. Bellinger 20-June-2009

2. Transfer Lines: Positions
of 12 DCOPS
Lasers at ME+4
and ME-4
shine axially
Establish
relative X,Y
of the transfer
plates, and thus
the SLM ends
SLM example Y X
James N. Bellinger 19-June-2009

3. DCOPS along Transfer Lines
Mounted on MABs
Minus Endcap
Plus Endcap
CMS Z
James N. Bellinger 19-June-2009

4. CRAFT Results
The laser control program failed. Only one half of one Transfer Line was complete
Each side has a crosshair laser pair. Only one of each pair threaded across completely
Impossible to fit Transfer Lines.
SLM Lines worked, and results have already been shown
James N. Bellinger 19-June-2009

5. First Transfer Line Data
11-June-2009 after closing
After midnight run
Expert “PickLine” tool rather than the DAQ
James N. Bellinger 20-June-2009

6. Sample Good Transfer Line alignment data
Plus Laser, Plus Endcap, Transfer Line 1, CCD0
James N. Bellinger 20-June-2009

7. Sample Bad alignment data
Plus Laser, Plus Endcap, Transfer Line 2, CCD0
James N. Bellinger 20-June-2009

8. First Results: Disk positions
YE+3 held fixed as a reference
Errors are Cocoa-only
Plus Endcap only
Name
X-shift (mm)
Y-shift (mm)
rZ (mrad)
YE+1
-2.35 ± 0.44
3.75 ± 0.32
0.34 ± 0.03
YE+2
0.43 ± 0.24
1.08 ± 0.20
0.75 ± 0.03
James N. Bellinger 20-June-2009

9. Data from Complete Transfer Line
Taken after midnight 17-June
Many lasers thread all the way through: Xiaofeng’s first pass at alignment was good.
James N. Bellinger 20-June-2009

10. Good example ME+4 ME+1 YB+3 YB+1 Plus Laser ME-2 YB-1 ME-4 XFER 1
CCD 1
James N. Bellinger 20-June-2009

11. Laser in the other direction
Readout
glitch
Minus
Laser
XFER 1
CCD 1
James N. Bellinger 20-June-2009

12. Limitations
MAB positions do not measure YB disks w/o additional information
Transfer Plate calibrations are not included here
Beam alignment isn’t perfect yet
James N. Bellinger 20-June-2009

13. Both lasers, both endcaps, both ends fixed
Cocoa fit
Both YE+3 and YE-3 disks held fixed
Name
X shift (mm)
Y shift (mm)
Zrot (mrad)
YE+1
-1.73
1.72
0.29
YE+2
-0.38
0.38
0.62
YE+3
0 (fixed)
YE-1
-2.82
0.49
-0.01
YE-2
-0.05
0.54
-0.69
YE-3
James N. Bellinger 20-June-2009

14. Both lasers, both endcaps, one side fixed
Cocoa fit
Only YE+3 held fixed
Don’t have enough of a handle
Rotations are similar to “both fixed”
Name
X shift (mm)
Y shift (mm)
Zrot (mrad)
YE+1
-0.47
1.00
0.28
YE+2
0.01
0.62
YE+3
0 (fixed)
YE-1
3.29
-2.27
-0.09
YE-2
6.70
-2.52
-0.78
YE-3
7.33
-3.37
-0.10
James N. Bellinger 20-June-2009

15. What’s wrong? Is it fixable?
Misalignments (Transfer 4 almost perfect, 5 and 6 half perfect, rest need work)
Laser adjustment will be attended to. It works now
Ambient light hurts in some locations
By next week should be able to turn off projectors
Shadowing is not a huge problem: paired redundant CCDs mean the other one is OK
Non-optimal filters
Nothing we can do about this now
Relative only; no CMS reference yet
James N. Bellinger 20-June-2009

16. Plans Realign the lasers using picomotors
Use Link fits and sensors in ME1/2 and the outer MABs to get CMS reference X/Y
Define DCOPS wrt MABs and MABs wrt tracker to pin down relative positions
James N. Bellinger 20-June-2009

17. BACKUP
James N. Bellinger 20-June-2009

18. Misalignment of one of the crosshair pair
“Up”-CCD
Laser at ME-4
Profiles become useless here
“Down”-CCD
James N. Bellinger 20-June-2009

19. Ideal View From Crosshair Laser
James N. Bellinger 19-June-2009

20. Real World
James N. Bellinger 19-June-2009

21. Shadowing of One CCD Leaves Other CCD OK
James N. Bellinger 20-June-2009