M. Gilchriese

Disk Geometry

January 18, 2005

M. Gilchriese2

ATLAS Coordinate System

M. Gilchriese3

The Parts

• Modules on disk sectors – Ron’s talk

• Sectors mounted on rings

• Rings mounted into disk frame sections

• Disk frame sections joined to barrel section(barrel to disk alignment)

• Pixel mounts attached to plate at ends of disk frame section

• Pixel mounts engage Pixel Support Tube(PST)

• PST(barrel) mounted to SCT barrel structure

• SCT attached to TRT

• TRT mounted on rails inside cryostat

M. Gilchriese4

Ideal Module Locations on Disk

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The Rings

Adjustable mounts glued into frame

Sectors precisely bolted to ring

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Ring Survey

• All rings were surveyed literally years ago using the SmartScope

• However this was done before the final mounts were in place(just pins used).

• This translates into a small uncertainty in the 0,0 location that we propose is done in the alignment software.

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Ring 3(C3)Bushing Radii 3-hole 2-hole Angle CircumSector Radii Deltas Separation Dev separation Dev Angle Dev Dev x y Diameter Dev

1 155.95323 -0.047 172.499 -0.001 -0.004 20.360 154.6185 312.048 0.0481 164.95673 -0.043 80.7503 0.000 157.488 -0.012 -0.035 63.159 152.3866 330.053 0.0531 155.95517 -0.045 142.490 -0.010 -0.027 94.961 123.7109 312.031 0.0312 155.9625 -0.038 127.477 -0.023 -0.062 123.771 94.8945 312.026 0.0262 164.98223 -0.018 80.7497 0.000 112.479 -0.021 -0.060 152.447 63.0809 330.038 0.0382 155.99479 -0.005 97.474 -0.026 -0.072 154.670 20.2901 312.033 0.0333 156.03179 0.032 82.466 -0.034 -0.092 154.685 -20.4573 312.070 0.0703 165.01825 0.018 80.7612 0.011 67.475 -0.025 -0.071 152.430 -63.2151 330.050 0.0503 156.04302 0.043 52.470 -0.030 -0.082 123.747 -95.0579 312.050 0.0504 156.057 0.057 37.468 -0.032 -0.088 94.932 -123.8614 312.032 0.0324 165.08142 0.081 80.7446 -0.005 22.479 -0.021 -0.060 63.119 -152.538 330.055 0.0554 156.07534 0.075 7.484 -0.016 -0.045 20.328 -154.7459 312.036 0.0365 156.09467 0.095 172.489 -0.011 -0.029 -20.404 -154.75545 165.0963 0.096 80.7581 0.008 157.496 -0.004 -0.012 -63.191 -152.52455 156.07562 0.076 142.504 0.004 0.010 -95.005 -123.82886 156.06326 0.063 127.510 0.010 0.026 -123.798 -95.02596 165.0556 0.056 80.7552 0.005 112.513 0.013 0.037 -152.477 -63.19836 156.03776 0.038 97.518 0.018 0.049 -154.696 -20.41587 156.03813 0.038 82.511 0.011 0.030 -154.707 20.33747 165.03162 0.032 80.7646 0.015 67.513 0.013 0.038 -152.484 63.11977 156.00748 0.007 52.511 0.011 0.029 -123.787 94.94868 155.97495 -0.025 37.511 0.011 0.029 -94.974 123.72578 164.9739 -0.026 80.7487 -0.001 22.511 0.011 0.032 -63.162 152.40398 155.96065 -0.039 7.505 0.005 0.014 -20.371 154.6245

Average 0.022 0.004 -0.007 -0.019 0.043Stdev 0.048 0.007 0.017 0.047 0.013

Corner Angle CircumBlock Radii Dev Angle Dev Dev

Top 179.953 -0.047 0.001 0.001 0.002 0.0021 179.9525Rt 180.003 0.003 90.020 0.020 0.063 180.0028 -0.0632Bot 180.072 0.072 -179.996 0.004 0.014 -0.014 -180.072Left 180.046 0.046 -90.011 -0.011 -0.034 -180.0457 -0.0337Average 0.018 90Stdev 0.052

Measured Nominal Deviation Center X Center YCircle diameter thru outer 3mm holes 330.0375 330 0.0375 -0.0241 -0.1002Circle diameter thru inner 3mm holes 312.0407 312 0.0407 -0.0159 -0.0628

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Frame is Drilled

ZDRILL

2.3729.550

ZBARREL+ENDCONE

Disk Z(IP) Z(DRILL)1 495 82.62 580 167.63 650 237.6

Z(BARREL+ENDCONE) 424.31Z(RINGCENTERTOBUTTON) 9.55Z(SECTORCENTERTOBUTTON) 2.372

XZIP

2.000.70

NOT TO SCALE!

Z(Barrel+Endcone) is measuredOther numbers are averages ofmeasured values.We could correct sector by sectorand ring-by-ring using measurements.The corrections would be max about 20 microns

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Ring and Mounts Glued

• Precision tooling is used to glue the ring-part of the mounts into the rings.

• Different tooling is then used to position the rings and glue part that goes into the frame. The tooling determines the ring position. We believe this was accurate to roughly 15 microns but no survey has been done(and would be hard to improve on this accuracy anyway)

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Disk Insertion

• This will utilize pretty much the same tooling that was used to glue the ring mounts into the frame.

• Thus the Z-locations will be identical to just bare rings.• The X-Y locations might vary, since the mounts have to be backed out and

then screwed in when the ring is in position.• We will try this more to understand the reproducibility.• This will also give us a measurement of the ring hole locations relative to

the barrel endcones – a starting point on barrel-disk alignment

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Frames and Pixel Mounts

• The ring locations will be “transferred” to the pixel mounts through the EndFrame

EndFrame is pinned and boltedto the barrel frame

EndPlate is bolted to EndFrame and pixel mounts are aligned(pinned) to EndFrame. The four mounts are adjusted to lie within a plane.

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Support Tube

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Current Plan

• Review ring survey data(ring for disk 3, side C) by Jan. 24.• Jon and I are doing this.• Measure reproducibility of rings in end-frame and develop

simple(non-CMM) means to reference to pins in EndFrame by March.

• Do not survey modules on disks – sectors on rings. Too risky.• Practically this means taking the sector and ring measurements

and creating a new XY “drawing” – actually a table - for each module.

• Z is more complicated but much less sensitive. Note that forces from pipes and cables will deflect sectors by amounts that cannot be measured during assembly – no access.

• We need to decide how to use module-on-sector Z measurements.