1. Status and Plans for Endcap Hardware Alignment
James N. Bellinger
University of Wisconsin-Madison
2-February-2011
James N. Bellinger 2-February-2011

2. DCOPS Sensors with Laser
A crosshair laser (a pair of lasers
each shining through a cylindrical
lens) illuminates each of the
DCOPS in turn along the line
DCOPS
Laser
James N. Bellinger 2-Feb-2010

3. Stability and Precisionmm
The DCOPS system is
capable of good precision.
Individual events show
variation in fit, especially with
relaxed quality cuts, but the
averages show appropriate
stability.
The question of whether the floor
was sagging under our disks was
answered quickly: Variation with
time is less than 100µ
Time (seconds in epoch)
Position of Transfer Line 1
ME+3 Radial Offset
wrt ideal center
Loose quality cuts
James N. Bellinger 2-Feb-2011

4. Prokofiev 2010 Fit tracks PG closely
R-j Hand Fit Residuals (offsets) for SLM Lines
ME+/-2,3, B = 0
Fit tracks PG closely
Fit=blue, PG=red mm
Prokofiev 2010
Agreement between hand fit and PG data is about of 0.5 mm
PG data is good enough to validate COCOA fit.
O.Prokofiev
11/20/2018

5. Z-Bending consistent ME2/3 and with ANSYS FEA and ME1
ANSYS ests
SLM1
SLM2
SLM3
YE1 ests
B=3.8T
Samir 2009
CSC & DPG Meeting - S. Guragain
June 16, 2009

6. Validation: SLM Compare 0T fits to photogrammetry:
RMS of order 1mm in X or Y in SLM
We believe we can do better than that: Oleg’s work shown earlier
930µ
ΔxCMS
James N. Bellinger 2-Feb-2011

7. Transfer Lines Measure relative disk shift and rotation
Local coords
Axial lasers link the DCOPS on
transfer plates from disk to disk
Fit each of the 6 laser lines in its
two local coordinates: “radial”
and “tangent”
For a station plot residual vs line # and fit
for a sine+constant. The amplitude is the disk
shift, the phase tells the direction of shift and the
constant (for the tangent fit) is the Z-rotation ∙ radius
Measure
relative disk
shift and rotation
James N. Bellinger 2-Feb-2011

8. Transfer Line Fit Residuals Measure Disk Shifts, Z-rotations
YE2 (tangent)
YE2 (radial)
Residual (mm)
Residual (mm)
Failed to reconstruct
Both ME+3 and
ME+2 plotted
YE2 is shifted wrt YE3 by 4.5mm
in 130º direction. Z-rotation is .4mrad
YE1 is shifted wrt YE3 by 4.9mm
in 205º direction. Z-rotation is .5mrad
YE1 (tangent)
James N. Bellinger 2-Feb-2011

9. Transfer Lines Transfer Lines connects
Endcaps
Barrel MABs
YB2: measured by Link and Barrel
YB0: only measured by Barrel
Compare relative positions of MABs
Give Endcap Transfer Points positions in space wrt the Link MABs
Gives each Transfer Line
2 fixed points in space
James N. Bellinger 2-Feb-2011

10. Plans Hardware Software Integration
The Minus side Link disk is now in the proper location, and their analysis is in progress! The mislocation was a major handicap in last year’s analysis.
Software
Integration
James N. Bellinger 2-Feb-2011

11. Hardware Work by Xiaofeng
Repair broken picomotors
Repair accessible broken DCOPS
Align Transfer Line lasers for 0T
get good data (this time!)
Verify all SLM lasers after T1 installation
Dismount/remount ME4/PT5 lasers/DCOPS for disk moving
DONE
James N. Bellinger 2-Feb-2011

12. Hardware Plans
Realign Transfer Line lasers to estimated positions for 3.8T (next week)
When we have a long “technical stop” (not feasible at this time)
Fix broken DCOPS (inaccessible for now)
Align SLM for 3.8T instead of current compromise
Replace transfer line laser
James N. Bellinger 2-Feb-2011

13. Software Plans: Barrel Twist
TB=track-based
HW=HardWare
There is also
a compression
in Z, but Endcap
studies have no
sensitivity to MAB Z
Barrel hardware alignment and barrel tracking don’t agree: 4mm relative “twist” end to end
James N. Bellinger 2-Feb-2011

14. Resolving the Barrel Twist
What part of the barrel twist is real?
Barrel/Link hardware measurements are consistent with each other
Tracking fits are consistent with each other
Transfer Line measures outer end of MABs
Can fix MABs relative to each other
Can align MABs to Endcaps and look for shifts
Independent check
James N. Bellinger 2-Feb-2011

15. Software Projects Consistency check for calibration numbers Wisconsin
Revisit the Transfer Line fit—MAB model has a problem Wisconsin
Validate Cocoa fitter with an alternative fit to SLM (in progress) Wisconsin
James N. Bellinger 2-Feb-2011

16. Integration Plans New tracking model by Pivarski under test
Integrates relative chamber positions from SLM fits (4 chambers per SLM) as a weighted constraint in the overall fit. Florida Tech
James N. Bellinger 2-Feb-2011

17. Automation of Processing
Most of the machinery for Cocoa processing is in place and tested on lxplus
Partition data into parallel sets
Merge link information
Process Cocoa, retrieve information and generate XML fragment
No substitute for a human reviewing the events—DQM doesn’t catch everything
Event transfer isn’t automatic yet. TBD
Inserting Link fit information isn’t automatic yet. TBD
James N. Bellinger 2-Feb-2011

18. Summary Hardware: Software:
aside from a few DCOPS the system is working, will be ready for 3.8T next week
Software:
SLM processing machinery—in place
Transfer Line to test barrel twist—in progress
Integration of hardware fit in tracking—under test
James N. Bellinger 2-Feb-2011

19. BACKUP
James N. Bellinger 2-Feb-2011

20. Disk Sagging No sign of sagging. Small changes with initial turnon.
Poor profile
No sign of sagging. Small
changes with initial turnon.
Equal time intervals not equally
populated
James N. Bellinger 2-Feb-2011

21. ANSYS Figure
James N. Bellinger 2-Feb-2011

22. Accuracy Checks with DCOPS
Evaluate the following discrepancies:
For DCOPS targets in all 3 dimensions:
Δx = xPG – xreco, Δy = yPG – yreco, Δz = zPG – zreco
If all were “perfect”, we’d expect Gaussians:
centered at 0
 = PG  reco = 300 m  250 m = 400 m
ΔxCMS
Samir, 2008
930µ
ΔzCMS
ΔyCMS
430µ
1090µ
- S. Guragain
26 Feb 2008

23. Fits for ME+3 and ME+2 Tangent Direction of Transfer Lines
James N. Bellinger 2-Feb-2011

24. More Software Projects: Search for Twist
Hybrid tracking + hardware reconstruction
Predict where chambers are
Defines DCOPS positions
SLM reconstruction gives Transfer Plate (rphi only)
TP rphi for ME2 and ME3 gives base for projecting Transfer Lines into MAB
Compare Plus and Minus projections into MABs, look for twist
James N. Bellinger 2-Feb-2011

25. Look for Evidence for Twist in Offsets
If twist is real, should see
offset in projections into MAB
Extrapolate line
James N. Bellinger 2-Feb-2011

26. Compromises SLM lasers only adjustable when field off
Time-consuming to realign these
Selected a compromise alignment that could be tested in 0T and still work in 3.8T
Not ideal for either
James N. Bellinger 2-Feb-2011

27. Z Sensors
Two limited-effort attempts to get the Z- sensor model working failed.
We use a differential approach instead.
Assume Z from assembly survey is correct and calculate Transfer Plate positions
Use change in Z-sensor from 0T to 3.8T to predict the change in Transfer Plate positions
Not urgent enough to redirect already insufficient manpower to solve the problem.
James N. Bellinger 2-Feb-2011