1 James N. Bellinger University of Wisconsin-Madison 27-November-2009 Status of Transfer Line Reconstruction James N. Bellinger 27-November-2009

2 Not in Person 27-November, the day after US Thanksgiving, is a mandatory furlough day for University of Wisconsin employees. To give us a salary cut without violating various labor contracts, management devised a “furlough” plan whereby everybody becomes an hourly employee for the week and is told to stay home for a day and not even think about working, logging in, etc.

3 Data Most of the Transfer Line lasers are well aligned. The best illuminated is Line 1, and the worst is Line 2 The following shows Line 1 All data used in this report is 3.8T from an event in October – One DCOPS reading failed and was replaced with another from a run 8 hours earlier James N. Bellinger 27-November-2009

4 Transfer Line 1, Laser 1 James N. Bellinger 27-November-2009 CCD 1 and 3 are top two rows, CCD 2 and 4 are bottom Red curve is the fit to the profile Laser

5 Transfer Line 1, Laser 2 James N. Bellinger 27-November-2009 Laser

6 James N. Bellinger 27-November-2009 Photogrammetry and the Transfer Line The SLM DCOPS position wrt the disk center The disk centers when the disks were being closed The Transfer DCOPS position wrt the SLM The relative position of points on the Transfer Plate – Also available from drawings: agreement was good enough that I use the drawings

7 James N. Bellinger 27-November-2009 Locating the Transfer Line Link can give the outer MAB positions in (x,y,z) wrt a tracker body reference PG can give us an estimate of Z for the Endcaps – Analog sensor reconstruction from the MAB on is not yet ready Combining these can give us (x,y,z) for measured chambers

8 James N. Bellinger 27-November-2009 Validating the Transfer Line The relative PG positions at 0T can be compared to special runs taken at 0T. If the relative positions of the Transfer DCOPS are similar in both cases, we can assert that the two agree to within that error. The Link information gives us fixed points in space (9 instead of 12) to tie the Transfer Lines to the tracker. We can estimate disk rotations and compare to PG.

9 James N. Bellinger 27-November-2009 Validating the Transfer Line: Problems Results: I reported earlier that I was not getting clear correlation between the relative positions of the DCOPS as found on the transfer lines and as measured in PG. We tuned our transfer line lasers for 3.8T, and don't have a great deal of good data at 0T. Recent data is not much use.

10 James N. Bellinger 27-November-2009 Consistency: Differences of Residuals Laser Number i (1 or 2) has slope S i and intercept I i Z position at station j is Z j Shift of station from ideal = X j Laser profile center is at S i Z j + I i Ideal Measurement M ij = S i Z j + I i – X j Z X Residual: R = M – fitslope Z – fitintercept R 1j – R 2j is independent of the laser slope and intercept Plus EndcapMinus Endcap MAB DCOPS

11 Consistency 2 We can thus get some measure of how well we are able to measure a position by looking at the distribution of differences of residuals. Each station has a measurement (for Line 1) Best fit for line through them for Laser1, then Laser 2 Subtract residuals using fit with Laser 1 from those with the fit with Laser 2 Rejoice (or not) James N. Bellinger 27-November-2009

12 Plots of residual differences Treat Up/Down and Left/Right fits separately Treat each Transfer Line separately: 1, 2, 3 across top; 4, 5, 6 across bottom Left/Right CCDs measure radial positions Up/Down CCDs measure Rphi, either in positive or negative direction depending on DCOPS orientation James N. Bellinger 27-November-2009

13 Left/Right Residual Differences James N. Bellinger 27-November-2009 Fit L/R CCD positions, for each laser, then difference of residuals Ideally =0 Line 2 is bad Difference of residuals in mm Line 1 Line 3 Line 4 Line 6

14 Up/Down Residual Differences James N. Bellinger 27-November-2009 Line 2 is bad Difference of residuals in mm Line 1 Line 5

15 Summary of Residual Differences LineUp/down = RphiLeft/right = radial 1450 µ300 µ 2 BAD18mm7.2mm 3230 µ2.3mm 4360 µ950 µ 5360 µ620 µ 6320 µ1.6mm James N. Bellinger 27-November-2009

16 Radial Fits From Cocoa James N. Bellinger 27-November-2009 There is a bug in the plotting Notice that the hit and fit to the hit are close. The display is buggy but the resulting fits are good. How good? Error bars are too small to see

17 Laser Fit Residuals for Line 1 James N. Bellinger 27-November-2009 Tight central core of well- measured points: 500 µ Scattering of less good points. Measured-Fit in mm

18 Compare CCD measurements James N. Bellinger 27-November-2009 CCD1-CCD3 or CCD2-CCD4 if both in a pair have good profiles. Only 28 of 48 do, the rest have one side shadowed. RMS =320 µ Difference between CCD measurements, mm

19 Plan Take fit Transfer Point positions and plug these into the Endcap model – Verify that iteration works correctly Use Endcap models to find fit chamber (x,y) Need agreed-on plan for what to provide: – Only (x,y,z) for measured chambers How to do this with usual tools? – Define some interpolation for the rest Find out what Inner MAB numbers are useful for the Barrel group James N. Bellinger 27-November-2009

20 BACKUP MATERIAL James N. Bellinger 27-November-2009 Recall that ME1 and Outer MAB Z-positions are very close. This makes them hard to distinguish in the ? vs Z plots

21 Up/Down Residual consistency James N. Bellinger 27-November-2009 Line 2 is bad CMS Z in mm Difference of residuals in mm

22 Left/Right Residual Consistency James N. Bellinger 27-November-2009 Difference of residuals in mm CMS Z in mm

23 Up/down Residual Pulls James N. Bellinger 27-November-2009 Differences of residuals/error

24 Left/right Residual Pulls James N. Bellinger 27-November-2009 Differences of residuals/error

25 Good and Bad Lines Transfer Line 1 is the best measured at 3.8T Transfer Line 2 is the worst Even Line 2 is mostly good! James N. Bellinger 27-November-2009

26 Transfer Line 2, Laser 1 James N. Bellinger 27-November-2009 No connection to far station Harmless glitch: I used data from earlier event here

27 Transfer Line 2, Laser 2 James N. Bellinger 27-November-2009 No connection to U/D for two farthest stations

28 Lasers Slight tweaking needed, otherwise in generally good shape James N. Bellinger 27-November-2009