Transfer Line and CSC Rφ Reconstruction James N. Bellinger University of Wisconsin-Madison 6-December-2009 James N. Bellinger 6-December-2009

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 6-December-2009

DCOPS along Transfer Lines Mounted on MABs Minus Endcap Plus Endcap CMS Z James N. Bellinger 6-December-2009

Transfer Lines: Positions 2 6 Transfer Lines 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 3 SLM example 1 4 Y 6 X 5 James N. Bellinger 6-December-2009

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 6-December-2009

Transfer Line DCOPS Up/Down CCDs measure Rphi, either in positive or negative direction depending on the DCOPS orientation Left/Right CCDs measure radial positions Transfer Lines are independent of each other UP CCD RIGHT CCD LEFT CCD DOWN CCD Radius direction James N. Bellinger 6-December-2009

Purpose of Transfer Lines Outer MAB positions are defined by Link wrt the tracker body Using Outer MAB positions to define lines in space, determine where the Transfer Plates are in space Using Transfer Plate positions determine the positions of the measured Endcap chambers Determine an outer position on the Inner MABs as a cross-check for the Barrel James N. Bellinger 6-December-2009

Transfer Line 1, Laser 1 Laser Plus Endcap MABs Minus Endcap CCD 1 and 3 are top two rows. They measure Rphi CCD 2 and 4 are bottom two rows. They measure R The red curve is the fit to the profile At each station (column) at least one profile within each pair is good James N. Bellinger 6-December-2009

Transfer Line 1, Laser 2 Laser Plus Endcap MABs Minus Endcap CCD 1 and 3 are top two rows. They measure Rphi CCD 2 and 4 are bottom two rows. They measure R The red curve is the fit to the profile At each station (column) at least one profile within each pair is good James N. Bellinger 6-December-2009

Photogrammetry and Drawings PG measured the disk centers PG measured the Transfer DCOPS position wrt. the disk center The relative position of points on the Transfer Plates was taken from drawings James N. Bellinger 6-December-2009

Locating the Transfer Line Link can give the outer MAB positions in (x,y,z) wrt a tracker body reference PG gives us an estimate of Z for the Endcaps Still working on Z-sensor reconstruction Combining these can give us (x,y,z) for measured chambers James N. Bellinger 6-December-2009

Simple Use of the Transfer Line The Link information gives us fixed points in space (in principle 12) to tie the 6 Transfer Lines to the tracker. With lines fixed in space we can use averages of Transfer Line positions on each disk to estimate disk rotations James N. Bellinger 6-December-2009

Radial Fits From Cocoa Yellow lines locate DCOPS apertures Notice that the hit and fit to the hit are close. The fits are good. How good? Plus laser Minus laser Green circles are measured hits Red diamonds are fit hits Error bars are too small to see James N. Bellinger 6-December-2009

Summary of Fit Residuals Line Up/down = Rphi Left/right = radial 1 950 µ 310 µ 2 Poor illumination 1.74mm 1.31mm 3 1.82mm 4 430 µ 680 µ 5 660 µ 6 560 µ Left/Right CCDs are illuminated by one pair of laser fans, and Up/Down CCDs are illuminated by the other pair. I look at them separately here. In Transfer Line 3 one of the lasers is not perfectly aligned, and in 2 both sets need adjustment. The next slide plots both types of CCD residuals together. Oleg finds 110µ with extra data quality cuts James N. Bellinger 6-December-2009

Laser Fit Residuals for Line 1 Tight central core of well- measured points: 120 µ Scattering of less good points. Core fit agrees with Oleg RMS=490 µ Measured-Fit in mm James N. Bellinger 6-December-2009

CCD Measurement Consistency If neither of a pair of CCDs is shadowed, they provide independent measurements of the laser position at that point, subject to Tilting of the transfer plate expected to be small Tilt of the laser fan itself measured in Cocoa, ignored here Variation in CCD position within the DCOPS of order 100 µ RMS James N. Bellinger 6-December-2009

Compare RAW CCD measurements for Line 1 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 =310 µ includes laser tilt and calibration variation! Difference between CCD measurements, mm James N. Bellinger 6-December-2009

Disk rotations Averaging the reconstructed DCOPS centers on each disk gives me rotations of the disks. Knowing MAB positions wrt tracker means these should be real rotations James N. Bellinger 6-December-2009

Disk rotation results Independent measurements of the same disks. Station Rotation in phi about Z (mrad) Distance of shift (mm) RMS of shifts (mm) ME+4 (YE+3) -0.45 -3.3 2.9 ME+3 (YE+2) -1.16 -8.4 2.2 ME+2 (YE+2) -1.00 -7.2 2.1 ME+1 (YE+1) -0.81 -5.8 ME-1 (YE-1) 0.35 2.5 6.7 ME-2 (YE-2) -0.73 -5.3 3.8 -0.344 -2.5 5.9 ME-3 (YE-3) 0.19 1.3 3.6 Independent measurements of the same disks. YB+2 and YB-2 MAB positions are the references. James N. Bellinger 6-December-2009

Chamber Positions We generated ZCMS positions and YLocal rotations for all CSC for CRAFT09 data Himali has been studying XCMS /YCMS CSC positions Machinery is in place to generate positions for measured CSC once we validate the Transfer Line reconstructions with PG σ=159µ The rest are similar James N. Bellinger 6-December-2009

ME-4 SLM1 Chamber Rφ Shifts with Field Off/On Animated GIF Will not work in PDF Average Shift=20µ Relative CMS Rφ (mm) Plots from Himali James N. Bellinger 6-December-2009

Summary The positions of the Transfer Plates are reconstructed to within about 500µ for most lines. We think we can do better. Ready to reconstruct chamber positions as soon as group approves Transfer Plate positioning Transfer Line 2 laser tweaking will improve the data James N. Bellinger 6-December-2009

BACKUP MATERIAL James N. Bellinger 6-December-2009

Transfer Line 2, Laser 1 (worst) Profile shape is odd No connection to far station Harmless glitch: I used data from earlier event here James N. Bellinger 6-December-2009

Transfer Line 2, Laser 2 No connection to U/D for two farthest stations James N. Bellinger 6-December-2009