1. MUON_EDR-06 (Alignment) Enrique Calvo Alamillo February 28-March 1, 2002 Link Mechanics: Status

2. 2 Index: Introduction. 1.- Components on the MAB structure. 2.- 2D Sensors on ME1/2 chamber. 3.- 2D Sensor on ME1/1 chamber. 4.- Elements in YN1 &  =3 Zone: ME11 Transfer plate and Link Disk. 5.- F.E.A. of the complete assembly: Link Disk + R/Z tubes. 6.- Installation strategy of the Link Disk. 7.- Calibration procedure of the Link Disk. Summary.

3. 3  Parameters and updated drawings for all elements on: MABs, and ME1/1,2 chambers.  Elements in YN1 &  =3 Zone: ME11 Transfer plate and Link Disk  Link Disk design and concept  FEA results  Installation strategy  Calibration procedure Updated Geometry description: Link System Parameters and Integration v.2, Feb02 (EDMS)

4. 4 1.- Components on the MAB structure Updated version of the link components on the MAB, reference parameters and drawings for all sensors mounts, are ready. LASER LEVEL Mount: -Unique mount for all 6 phi positions - Simple mechanics, no re-adjustment foreseen

5. 5 This shows the different Laser Level angular positions in the detector for +Z and –Z side. (View from IP) +Z -Z

6. 6 2D Sensor Mount: Incorporates diode, optics, and electronics driver into a single assembly of allocated overall dimensions.

7. 7 Proximity Sensor Mount: Minor changes wrt previous version.

8. 8 2.- 2D Sensors on ME1/2 chamber Drawing of the 2D Sensors on the ME1/2 chamber (including reference mounts on the corresponding island plates) are ready. Final cross- check with EndCap drawing still to be missing. 2D Sensor Mount: Design for the top and bottom sensors. As in the case of the MAB sensors, Incorporates diode, optics, and electronics driver into a single assembly of allocated overall dimensions.

9. 9 3.- 2D Sensor on ME1/1 chamber Mounts on the chamber frame with reference to the strips are established since long time.

10. 10 2D Sensor Mount: updated for the new sensor type. Incorporates diode and electronics driver.

11. 11 4.- Elements in YN1 &  =3 Zone: ME11 Transfer plate and Link Disk To avoid remote repositioning of the laser box, and at the same time reduce the effect of the iron distortion on the laser box sitting at eta=3, we have re-designed this region. The laser boxes are now housed on a disk of carbon fiber that will be fixed, with 6 arms, at the top of the YN1 at R=2630 mm, couple to the ME1/1 Transfer Plate. At this R position, the relative deformation between the 6 phi locations is relatively small. At installation the final positioning of the disk can be adjusted to compensate for static effects (gravity), installation and assembly tolerances. Out of the 6 points, 3 (at 15, 135 and 255 degrees) can be used to adjust the disk to the final position. We will be able to mount and to dismantle the Link Disk (all Laser Boxes) as a set. No intervention is foreseen when beam-pipe is in place. To avoid, as much as possible, active elements on the eta=3 region, we have attached the tubes running along eta=3 (Z-measurements) directly on the Link Disk.

12. 12 From the Magnet TDR (Figures 8.26, 8.27, 8.28 and 8.29), the distortion in the Z and Y direction, at the position on the top of the YN1, due to magnetic forces and gravity load are: - In Y, the motion is very similar at the 6 positions of the fixations. - In Z, the effect is like a rotation around the X-axis of  1 mrad from gravity, or  0.6 mrad when considering gravity+magnetic forces. This translates to a global rotation of the top of YN1 and therefore of the Link Disk assembly

13. 13 ME11 Transfer plate: The designed assembly has positioning tolerances of ± 2 mm in R, and Z, and ± 1 mm in Rphi.

14. 14 Position of the Disk wrt the EndCap iron.

15. 15 Details of the fixations of the Disk to the R/Z profiles, and Laser box.

16. 16 Assembly of the Laser box and direction of the beams.

17. 17 Design of the Z tube fixations: spherical bearing, and support point (at Z=4000mm).

18. 18 - 5.- F.E.A. of the complete assembly: Link Disk + R/Z tubes. Study of displacements and rotations due to gravity and T gradient (  5 degrees). The calculation is done for a structure composed by: - The disk supported by 6 arms to R  2700 mm by rigid fixations on the ME11 Transfer plate, and - 6 tubes on  =3 for the (z measurement) attached to the disk by a spherical bearing, and with a sliding guidance at Z  4000 mm.

19. 19 Materials: The Disk is a carbon fibre sandwich 20 mm thick, ( 2 mm skins (T300/3501-5) and 16 mm honeycomb (Nomex). The layout of the sandwich is the following: Skin1 (0 3 /90 3 /  45) SE, Honeycomb, Skin2 (0 3 /90 3 /  45) SE. The internal radius is 0.5 m and the external 0.65 m. The R profile is a rectangular profile of stainless steel (80 (rphi) x 40 (z) x 1.5(thick)) about 2 m long. The Z cylindrical tube is made of aluminum, with dimensions: Φ i 36 mm, Φ e 40 mm and 3.6 m long. Properties of the materials: Loads and constrains: The structure is loaded with 6 Laser Boxes (  0.8 Kg per Laser Box) at the angular positions: 15º, 75º, 135º, 195º, 255º and 315º, and at R~620 mm. It is inclined wrt gravity 0.01234 rad. The Disk is fixed to the R profiles at: 15º, 75º, 135º, 195º, 255º and 315º. The support points of the structure are on the top of YN1. These points suffer relatives displacements when powering the magnet. The distortion in the Z and Y direction (obtained from the previous table) is: In the analysis, it is assumed that YN1 suffers the same T gradient as considered for the Disk structure. Therefore the supports points at the top of YN1 will suffer the deformations induced by the temperature changes.

20. 20 The rectangular profile is uncentered on rphi wrt the Link Line by 25 mm, (the profile is not exactly radial). And it is not aligned, in Z, with the disk structure, by 10 mm

21. 21 The FEA, for +Z side, shows that the magnet distortions, at the different points, induce the following distortions on the Disk (and therefore the Laser boxes points): maximum relatives displacements are  1.5 mm, and maximum rotations  0.9 mrad. In all the FE calculations we have considered a simplified model (wire model instead of solid). We expect that the obtained deformations will be even smaller since part of them can be absorbed at the fixations to the disk.

22. 22 Displacement due to Gravity load only (m). Displacement due to Gravity load and Temperature 5ºC (m).

23. 23 Rotations due to Gravity load only (m). Displacement due to Gravity load and Temperature -5ºC (m).

24. 24 Rotations due to Gravity load and Temperature –5ºC (m). Rotations due to Gravity load and Temperature 5ºC (m).

25. 25 At the installation, without taking into account the effect of the magnet in the support points, the results from FEA, for +Z side, show that the assembly (Disk and radial arms) will deform due to gravity such that: maximum displacements are  0.4 mm, and maximum rotations  0.4 mrad. In all the FE calculations we have considered a simplified model (wire model instead of solid). We expect that the obtained deformations will be even smaller since part of them can be absorbed at the fixations to the disk.

26. 26 Displacement due to Gravity load only (m). Displacement due to Gravity load and Temperature 5ºC (m).

27. 27 Rotations due to Gravity load only (m). Displacement due to Gravity load and Temperature -5ºC (m).

28. 28 Rotations due to Gravity load and Temperature –5ºC (m). Rotations due to Gravity load and Temperature 5ºC (m).

29. 29 6.- Installation strategy of the Link Disk. During installation, and to guarantee the functionality of the system, we consider two checking/adjustment steps: - Cross-check the pre-calibrated internal degrees of freedom in the Disk (location of Laser boxes within the Disk and relative orientation of the laser beams) wrt the real position of the sensors in the detector: Before closing the EndCap disks, laser measurement can be done using a Pre-installation Wheel similar to the Link Disk where we can confirm the correct relative position among the Laser boxes as well as the relative orientation of the radial and axial beams. We can cross check, if the laser beams hit on the center of the 2D sensor of the MABs and on the center of the Tracker elements. If the Pre-installation Wheel needs re-adjustments (known by meas) they can be translated to the Link Disk (or the rest of the components). - Global positioning of the Disk on YN1 A global adjustment of the Disk (position & orientation) is foreseen using three (out of the 6) fixation points at the top of YN1

30. 30 The Pre-installation wheel sends six pre-calibrated laser beams toward the MABs and others six pre-calibrated laser beams toward the Tracker (periscopes or entrance points into the Tracker volume). These laser beams simulate the Link lines in the detector. A first design of the pre-installation wheel has been done out of Alumium tubes (honeycomb sandwich it could also be possible). The drawing shows the distribution of components. Each laser beam might need to incorporate a re-adaptation system, to adjust the beam to the correct position. The present design allows three displacements and two rotations (acting on the different screws) to re-position the beams.

31. 31 At installation. the (calibrated) pre-installation wheel can be place at its position (same as for the Link Disk when the detector is closed) in the detector but attached at the BARREL side with an auxiliary support structure on the temporal support of the beam pipe on the cryostat. The following figure shows the schematics for the +Z barrel side.

32. 32 7.- Calibration procedure of the Link Disk. We foresee to use a standard survey grid for the calibration/positioning of the laser beams of the wheel. The following figures show the proposed scenario. The first drawing shows the position of the wheel for the radial beams calibration, and the second for the calibration of the  =3 angle beams. The calibration procedure consist of placing the wheel, as shows the figure, to re-adjust four laser beams wrt the survey points. Once this is done, rotating the wheel by 120º wrt the center will allow to re-adjust the other two laser beams.

33. 33 In a second step we repeat the procedure for the  =3 angle beams by placing the wheel as shows in the figure.

34. 34 Summary - The mechanics for the different sensors mounts (at the MABs, and ME1/1,2 chambers) is designed and ready. Minor integration details will still be cross-checked following the evolution of the interface parts. - A new strategy for the region  =3 has been developed. The design of a Link Disk housing the Laser beams, and the FEA of the whole structure are well advanced. Up to day, the studies show acceptable results. The new design avoids, as much as possible, active components at the un-accessible region,  =3. This aspect imply a more complicated mechanics of the assembly. We have developed a installation strategy that allows to cross- check the functionality of the system before closing CMS. We have developed a calibration procedure of the Link Disk that can be done by using standard/precise survey techniques.