1. University of Wisconsin-Madison
Cocoa ME+1
James N. Bellinger
University of Wisconsin-Madison
18-Feb-2009

2. How close are we? Coded targets tell where chamber surface is
Hand calculation minus coded target
Poor agreement
Hand est-
PG z
ME+1/3/03
-7.76
ME+1/3/09
-3.70
ME+1/3/14
-3.68
ME+1/3/20
-4.77
ME+1/3/27
-2.09
ME+1/3/33
7.57 (bad)
James N. Bellinger 18-Feb-2009

3. ME+1/2 Outer layout Chamber Surface Target=3mm SensorBox = 63mm dowel
Sensor mount plate =10mm
Shim: 12.1mm outer, (4.6mm inner)
Mount plate = 6.35mm
DCOPS
Spacer = 35mm
Chamber frame plate: 6mm
Chamber Surface
For upper
Target top=reference
Frame = ref
Sensor center = ref-26 (=23+3)
DCOPS center = ref
Surface = DCOPS center+0.276
DCOPS dowel = ref-94.45
41.276mm dowel to center
James N. Bellinger 18-Feb-2009

4. ME+1/3 layout DCOPS Chamber Surface DCOPS center to dowel: 41.276mm
Mount plate: 6.35mm
Spacer: 25mm
Chamber frame plate: 6mm
Chamber Surface
James N. Bellinger 18-Feb-2009

5. Is something missing?
Original Cocoa number for +1/3 DCOPS to chamber surface seems to be wrong
The descriptions of the material involved in the DCOPS and ASPD mounting for the HSLM are laid out in in tree form in
The chamber frame information is from Wenman and I don’t have the construction drawings defining it.
James N. Bellinger 18-Feb-2009

6. Doing my own optimization
Use Link info to get ASPD top for ME+1/2 outer and the distancemeter position for the Transfer Plate
Use offsets from CAD drawings to reach DCOPS center positions
Include profile positions (not at center) and calculate a line joining the two points
Predict profile position at ME+1/3 DCOPS
Use profile positions and CAD information to predict chamber surface positions
James N. Bellinger 18-Feb-2009

7. Optimizing
Use the average of these two surface positions as an estimate of the surface at 0T
Subtract the coded target position (on surface), square and form a chi-squared
Sum for HSLM1-5 only: HSLM6 known bad
Variables:
X=additional distance between ASPD and DCOPS at ME+1/2
Y=additional distance between DCOPS and surface at ME+1/3
James N. Bellinger 18-Feb-2009

8. X variable definition X Chamber Surface Target=3mm SensorBox = 63mm
dowel
Sensor mount plate =10mm
Shim: 12.1mm outer, (4.6mm inner)
Mount plate = 6.35mm X
Spacer = 35mm
DCOPS
Frame plate: 6mm
Chamber Surface
For upper
Target top=reference
Frame = ref
Sensor center = ref-26 (=23+3)
DCOPS center = ref
Surface = DCOPS center+0.276
DCOPS dowel = ref-94.45
41.276mm dowel to center
James N. Bellinger 18-Feb-2009

9. Y variable definiton DCOPS Y Chamber Surface
DCOPS center to dowel: mm
Mount plate: 6.35mm
Spacer: 25mm Y
Frame plate: 6mm
Chamber Surface
James N. Bellinger 18-Feb-2009

10. Result 4.411X + 10Y = 44.172 If X=0 (ME+1/2 mount known perfectly)
Need 4.42mm extra between DCOPS and ME+1/3 surface
If Y=0 (ME+1/3 mount known perfectly)
Need 9.00mm extra between ASPD PG4 and DCOPS center.
James N. Bellinger 18-Feb-2009

11. Is the ASPD position wrong?
But
Photographs show the ASPD mounting, and it matches my understanding from the CAD drawings
Xiaofeng assures me he mounted the DCOPS directly under the mounting plate
No room for 9mm spacers at ASPD
Is the ASPD position wrong?
No. Celso finds agreement between PG and his P4 reference calculation
And..
James N. Bellinger 18-Feb-2009

12. ASPD P4 to chamber surface
ME+1/2 has coded targets also
Compare Cocoa 0T fit to coded target locations in Z
Suggests ASPD to surface is understood and OK
Cocoa-PG
ME+1/2/02
0.16
ME+1/2/08
2.45
ME+1/2/14
0.25
ME+1/2/20
-0.62
ME+1/2/26
0.65
ME+1/2/32
7.57 (bad)
James N. Bellinger 18-Feb-2009

13. Transfer Plate?
Trying the same trick with the Transfer Plate suggests that the DCOPS center is 8.7mm farther to the rear than I calculate from drawings AFFLp BLK etc
James N. Bellinger 18-Feb-2009

14. This afternoon
Redo model of line using PG points as reference instead of Link system references
Note that some of the PG alignment pin measurements are inconsistent with each other.
Fortunately we usually have the coded targets on the chamber surface to cross- reference with, and let us decide which to discard
James N. Bellinger 18-Feb-2009