1. University of Wisconsin-Madison
ME+1 hSLM Fits
James N. Bellinger
University of Wisconsin-Madison
3 December 2008

2. Summary Fits converge using Field on and field off data from CRAFT
DCOPS data
Link disk fit positions
Link laser sensor data
Z1 (distance to MAB) sensor data
Field on and field off data from CRAFT
Small bug remains with Z positions
James N. Bellinger 3-December-2008

3. Model x 6 DCOPS laser Z1 sensor: Transfer plate to MAB MAB YE+1
Illuminates 4 DCOPS
ME+1/3
MAB
YE+1
Need to refine Z
at this point
x 6
ME+1/2
Measures ME+1/2
Measures MAB
Ignore ME+1/1
in this model
Link laser: prism makes 2 lines
James N. Bellinger 3-December-2008

4. Some massaging required
Raw sensor values for
PT1 Z1
Distance from Transfer
to MAB
Select an appropriate
region, and use the
average value.
There is some drift
Ramping
field
3.8T
James N. Bellinger 3-December-2008

5. Positions Photogrammetry targets Chamber centers
Cocoa Field Off (at end of CRAFT) to PG values
Direct comparison only
Chamber centers
Field Off to Field On
Field Off to Ideal
Direct comparison and removing overall shifts
Field On to Ideal
James N. Bellinger 3-December-2008

6. PG Targets: ME+1/2 1.1mm 1.0mm 1.0mm 1.3mm 0.8mm X 1.0mm Y
James N. Bellinger 3-December-2008

7. PG Targets: ME+1/2 Z PROBLEM: Inconsistency
in the ideal target positions,
and Cocoa Z definition.
Investigating; should be
solved by end of the day.
James N. Bellinger 3-December-2008

8. PG Targets: ME+1/3 0.4mm 1.6mm 0.4mm 1.0mm Y X 0.7mm 1.4mm
James N. Bellinger 3-December-2008

9. PG Targets: ME+1/3 Z PROBLEM: Inconsistency
in the ideal target positions,
and Cocoa Z definition.
Investigating; should be
solved by end of the day.
James N. Bellinger 3-December-2008

10. Chamber Centers Ideal position Cocoa fit with field on
Cocoa fit with field off
No centers generated from PG targets yet for ME+1
James N. Bellinger 3-December-2008

11. Chamber centers ME+1/2 Difference between field off and field on
fit positions
Center pulled in
in Z by 8.1mm
James N. Bellinger 3-December-2008

12. Chamber centers ME+1/3 Difference between field off and field on
fit positions
No significant shift
in chamber center
in Z. Needs check!
James N. Bellinger 3-December-2008

13. Chamber centers in Z Ring 2 fits for Z Ring 3 fits for Z
James N. Bellinger 3-December-2008

14. Overall Shifts
If a ring is rotated, its PG and chamber positions will reconstruct away from the ideal.
Direct comparison of PG and COCOA fits is misleading because these rotations aren't taken into account—precision is better than it appears.
James N. Bellinger 3-December-2008

15. Removing Overall Shifts
Want to know shift relative to ring
Subtract off the overall misalignment of the disk/ring
Look at relative shifts, esp vs position around ring
Measures variation in relative mounting
MuonGeometryArrange tool
Calculates shifts of chambers, builds an overall shift of the ring
Shifts the ring and re-compares chamber shifts
Bug prevents comparing incomplete geometries to each other
James N. Bellinger 3-December-2008

16. Cocoa vs Ideal ME+1/2 Remaining deviations after ring realignment
Plot of deviations
as vectors starting
from chamber
centers. Scale at
top is length of
longest deviation.
Deviations of order
mm from field off
to field on. NOTE
that the scale
changes!
James N. Bellinger 3-December-2008

17. Cocoa vs Ideal ME+1/3 Deviations of order 0.1mm from ideal, and
from field off to
field on
James N. Bellinger 3-December-2008

18. Cocoa vs Ideal ME+1/2 Z
Variation in Z around the ring after ring shift is removed
James N. Bellinger 3-December-2008

19. Cocoa vs Ideal ME+1/3 Z
Variation in Z around the ring after ring shift is removed
James N. Bellinger 3-December-2008

20. Z shifts around ring No obvious pattern to relative Z shifts
Shifts are of order a few hundred microns
James N. Bellinger 3-December-2008