Status of Transfer Line Reconstruction University of Wisconsin-Madison James N. Bellinger University of Wisconsin-Madison 3-September-2010 James N. Bellinger 3-September-2010

Where do we stand? Cocoa fits seem to work: sometimes Hand fits seem to work But how do we validate these? Compare to each other (shown last time) Compare estimated MAB centers with Barrel/Link positions Fix outer MAB positions and angles Let inner MAB X,Y float, fix Z and angles James N. Bellinger 3-September-2010

Why Insist on the MABs? Survey of the transfer plates at 0T is not a reliable description of their positions at 3.8T. ME4 transfer plates seem to move outward in Z by about 2mm and inward in radius by a similar amount. This should make offsets for MAB DCOPS radially larger by about the same number in 3.8T compared with 0T. Not clear that they are. No fixed reference except via the MAB Can make assumptions and estimates using old magnet model, but I don’t trust them James N. Bellinger 3-September-2010

Possible systematic errors Errors in the outer MAB position are magnified projecting to ME4 Not sure how well known the YB-2 MABs are known. Link problems? James N. Bellinger 3-September-2010

Changes Revised DCOPS description for MABs Back to the box size and worked inward Found bug in standard DCOPS model: CCDs in rectangle instead of a square Many different apertures Revisited prediction of DCOPS position and tilt in each MAB James N. Bellinger 3-September-2010

Cocoa vs Barrel fit for Inner MAB Mean .05mm RMS .5mm Mean -.95mm RMS .8mm James N. Bellinger 3-September-2010

Internal Agreement with MAB Radial agreement is quite good: average disagreement is less than 50 microns, resolution is less than 500 microns. Rphi agreement is less good, but still far better than before: -.9mm average disagreement, with a little less than 800 micron resolution (was 2.6mm!) Is this consistent with MAB angular uncertainty? 300 microradian systematic tilt would do it James N. Bellinger 3-September-2010

Projecting to Endcap looks poor Expect O(+2mm) for stations ±3,±4 Expect O(-2mm) for stations ±1,±2 Expect some variation with line because disk bends like a potato chip Something in Cocoa is wrong? Doesn’t look like projection error, but doesn’t appear in ME4 fixed fits 0T PG position - fit James N. Bellinger 3-September-2010

Offsets for Line 1: Cocoa vs Hand Both have ME4 fixed Station dX (mm) Cocoa Hand fit dY (mm) ME+3 2.07378 2.520 -5.58365 -6.072 ME+2 2.06415 2.474 -4.66432 -5.098 ME+1 1.00499 1.220 -5.41692 -5.732 MAB+3 1.32987 3.855 -3.47646 21.982* MAB+1 -2.30884 3.528 0.357306 25.469* MAB-1 -1.29895 4.907 -2.51285 -0.214 MAB-3 1.74611 4.546 -0.113382 1.540 ME-1 1.02517 0.893 -5.25257 -5.361 ME-2 1.16804 1.462 4.50519 4.383 ME-3 0.11244 -0.040 3.85222 4.062 From last time MAB calcs not readily comparable here Agreement between hand and Cocoa for ME stations here better than .5mm ME stations are nearer laser! James N. Bellinger 13-Aug-2010

Tentative Conclusions The transfer line Cocoa model can reproduce the barrel model to very good (50micron) accuracy, and better than 500 micron precision. The transfer line model is symmetric with respect to CCD orientation—we should get the same kind of accuracy in the Rphi direction as well Hand fit mapping isn’t ready yet We can get agreement between hand fit and Cocoa to better than 500 micron precision in the Endcap as well. James N. Bellinger 13-August-2010

Time is Shorter (may be some grace) Priorities: Finish hand geometry match code Look for agreement with expectations Diagnose cocoa XFER line? Replace it? Revive the 0T fit: but note that single fits are not as accurate as a set of fits James N. Bellinger 3-September-2010

BACKUP James N. Bellinger 3-September-2010

Inner MAB Centers Details Station Line X CMS (mm) Y CMS (mm) -1 1 =MAB-1/1 -4283.799 -1547.740 2 =MAB-1/3 -804.133 -4462.263 3 =MAB-1/5 3466.716 -2924.658 4 =MAB-1/7 4273.782 1532.486 5 =MAB-1/9 802.673 4457.601 6 =MAB-1/11 -3471.526 2920.364 1 1 =MAB+1/1 -4287.763 -1550.902 2 =MAB+1/3 -800.623 -4463.791 3 =MAB+1/5 3470.535 -2925.653 4 =MAB+1/7 4279.828 1544.626 5 =MAB+1/9 799.829 4460.774 6 =MAB+1/11 -3462.137 2924.059 For reference James N. Bellinger 3-September-2010

0T COCOA fit vs Alignment Pin PG My new transfer plate positions SLM fits X_mine-X_PG mean 0.1mm RMS 1.1mm X_dave-X_PG mean 0.6mm RMS 1.9mm Slide from 26Mar2010 ME-2/SLM2 fits poorly for Dave’s #’s. Excluded here. James N. Bellinger 26-March-2010

Stability Feb-Apr MAB +3/1 DCOPS radial offset as a function of time Much more hour to hour variation than I find happy, but the averages are stable, and range far less than 1mm James N. Bellinger 3-September-2010

Refinements Take DCOPS orientation into account and use all 4 CCDs: eliminate some of the slop due to the laser tilts, which can be several hundred microns James N. Bellinger 13-August-2010