Proposal for the Barrel Alignment Upgrade

1. Proposal for the Barrel Alignment Upgrade Bencze György, Béni Noémi, Szillási Zoltán, Ujvári Balázs (ATOMKI, RMKI ) the Hardware Barrel Alignment Group This project is supported by Hungarian Research Fund (OTKA) NK 81447 .

2. Outline Two bigger topics: • Reinforcement of measurements in Sector 13 & 14 • Measurement of inter-wheel distances within Barrel Two minor items: • Additional PG targets/redesign PG targets on MABs • Programming extension to BoardPCs And a wish… • Incorporate DT temperatures into the Ali reco Barrel Alignment – Upgrade proposal 2

3. Reinforcement of alignment measurements in Sector 13 & 14 Barrel Alignment – Upgrade proposal 3

4. Diagonal connection Passive plane (6) Active plane (6) Muon chamber optical line Z bar (8 lines) MAB (36 pieces) Link line Schematicview of the Barrel Alignment CCD’s muon chambers MAB light sources (LED) • - Rigid structures (MABs, z-bars) • Video-camera boxes (on the MABs) • LED holders (called forks, • on the chambers) • Diagonal and Z-LED holders • (on the MABs and Z-bars) • - Board computers (one for each MAB) Barrel Alignment – Upgrade proposal 4

5. Sectors 13-14 for MB4 chambers Sector 13 Sector 4 Sectors 4 and 10 are measured at the –phi side only (by 4 MABs) Chambers in sectors 13 and 14 are measured at the +phi side only (by 2 MABs) X Sector 10 Sector 14 Barrel Alignment – Upgrade proposal 5

6. Results – what is expected What is measured (sect 13,14): z DT YB+2 YB-2 y Measurement point x MAB MAB MAB Transversal view Longitudinal view What is expected: Fair results in X and Z at MB+/-1,2, weak in rot_Z, therefore also in Y (depending on the chamber orientation), very weak in general for YB0. Barrel Alignment – Upgrade proposal 6

7. Results – COCOA-error study Mean and Max errors (COCOA-errors only but real measurement data): Mean Max In X (all chambers, micrometer) 26 61 In Z (YB0 excluded, micrometer) 23 34 In rot_Z (YB0 excluded, mrad) 1.9 2.0 Other rotations (all chambers): <0.3 mrad For YB0: In X: 61 micrometer; In Z: 2770 micrometer(!) In rot_Z: 13 mrad (!) As expected but here we have the numbers Barrel Alignment – Upgrade proposal 7

8. The proposal Put a MiniMAB with 2 cameras at the joint region looking inside the wheel. The cameras can observe the LEDs (already installed but not used so far). The MiniMABs can fix the DTs wrt. each other. YB+2 YB+1 YB0 YB-1 YB-2 Proposed MiniMAB arrangement: Sector 4 Sector 13 MAB MiniMAB Sector 10 Sector 14 Barrel Alignment – Upgrade proposal 8

9. MiniMABs Cameras identical to those used for chimney-chamber regions Two types: top and bottom d Carbon-fiber plate (5mm thickness) Camera distance „d”: Sector 13 Sector 14 (top) (bottom) 368 mm 457.4 mm Barrel Alignment – Upgrade proposal 9

10. Results of simulations, sectors 4 and 13 Worst case Barrel Alignment – Upgrade proposal 10

11. Results of simulations, sectors 10 and 14 Worst case Barrel Alignment – Upgrade proposal 11

12. What is needed 18 carbon-fiber plates to be bought (cheap) 36 video-sensors available from spares 36 lenses from spares (f=20mm) 36 camera-houses to be fabricated 4 board-PCs from spares* 2 CAEN A3006 LV modules to be bought (~12kCHF) 2 power distrib.+eth.switch parts (switch, connectors, box) to be bought, assembly needed In addition: Camera-box assembly, calibration MiniMAB calibration Cabling, installation Installation is possible during the next long shut-down when the barrel is opened. Free spaces for LV modules and 1U distrib. modules are OK * New BPC are to be installed only on YB±1. Otherwise use free ports of existing ones. Barrel Alignment – Upgrade proposal 12

13. Measurement of inter-wheel distances within Barrel Barrel Alignment – Upgrade proposal 13

14. Motivation • measurement of the distance between the barrel wheels is desireable during closure and magnet ramp • more sensor could also show wheel deformation (some hints from Barel Ali) Easiest solution is to put distance meters on the wheels and read them out through the BoardPC. (since it would require the least cabling work) Barrel Alignment – Upgrade proposal 14

15. Possible solutions • Laser displacement sensor: • quite expensive • needs digital • Voltage should be compatible with MAB, BPC Potentiometer: Sticks out -- vulnerable Barrel Alignment – Upgrade proposal 15

16. Possible solutions • device used by EndCap Ali is an analog one (and no more produced) • digital one needed (from different firm)(possible some serial comm, since PBC still has one free RS232 port) • candidate: Micro Epsilon (RS422) • firm has been contacted for technical & pricing details --- had an on-site meeting • whenknowthepricewecoulddiscusshowmanysensorswewant • can start magnetic & radhardtests • Mimmocan design mounting ≥ 1300 CHF/pc !!! Barrel Alignment – Upgrade proposal 16

17. Where to install MAB volume (or close to it) is a good candidate • only local cabling needed • wheel ref holes are close and could be used • Ref holes have very good surface and • used by Survey to define wheel  possibility to follow wheel movements in survey approach Barrel Alignment – Upgrade proposal 17

18. Conclusion • enormous number of devices would be needed for accurate wheel position/deformation measurements  Min 50kCHF (or rather above) • since Ali doesn’t have wheels (DTs only), these measurements would not improve • these devices are not good for closing either… We propose to abandon this project To tell the truth, we plan to be involved in a similar closing sensor, but: • less precise (~1-2 mm) • much less number • not radhard, not B tolerant • cheaper (HOPE!!!) Barrel Alignment – Upgrade proposal 18

19. Additional PG targets/redesign PG targets on MABs Barrel Alignment – Upgrade proposal 19

20. Motivation This is a minor item, but having large impact… • there is a discrepancy between the track and the hw alignments both in Z (2mm, scaling?) and phi-like torsion (3mm) • so far we have only indirect ways to test where it comes from • previous item wouldn’t solve this enigma, since Barrel Ali doesn’t have wheels. • torsion has gone, but was not solved by us! We need a direct external measurement possibility. Barrel Alignment – Upgrade proposal 20

21. What to do? It would be nice to measure all 6 dof of a MAB, but it is impossible  measure at least one point of it: ? These points are surely seen from outside Barrel Alignment – Upgrade proposal 21

22. What to do with them? How? • Survey group could measure Z coordinates of them (or at least Z distance) • Antje says precision is around 70 microns (discrepancy, we have ~ 2mm!) • Maybe they can measure phi position as well  answer for torsion… • If Z scaling found, its value can be used as a correction later. • Solution is cheap • Mimmo can design (probably the worn MAB definition targets are also to be changed at the same time) • New targets are needed to be located inside the MABs frame  needs access to them and probably to be done in ISR. Barrel Alignment – Upgrade proposal 22

23. Programming extension to BoardPCs Barrel Alignment – Upgrade proposal 23

24. Motivation and the solution • In last May we lost a Custom Board since its software got frozen • Problem is known, it is due to a bootloader that is designed to be able to upload new firmware if needed • Now, on 30 (out of 36) Custom Boards, bootloader is disabled (May problem happened on one of the remaining 6) • This prevents us from uploading new firmware… Solution: We would like to design and install a small device on BPC to solve it This item is very small, but also requires access to MABs… Barrel Alignment – Upgrade proposal 24

25. And finally a wish… Barrel Alignment – Upgrade proposal 25

26. Use TDT in Ali reco DT Calibration in ISR… • DT temperature varied between 19 and 24 degC • We have this data for all DTs Barrel Alignment – Upgrade proposal 26

27. Use TDT in Ali reco Alignment measurements in UXC… • Temperature on MABs varies between 19 and 26 degC • This is the T of air and not DT Tmeas ≠ Tcalib distance of alignment passages change  APE gets worse (αAl = 23.1 μm/K  …might be 100 μm/K on MB4!!) Barrel Alignment – Upgrade proposal 27

28. Use TDT in Ali reco Latest APE calculations σXlocal ~ 500μm (wrt. PG) We belive that APE could be reduced if actual chamber temperature could be used. (αAl = 23.1 μm/K  …might be 100 μm/K on MB4) • This would require to measure rather the real DT temperature than the air (MAB). • Measure the gas temperature? At the manifold on the chamber exit? • Aachen has a proposal for that. Barrel Alignment – Upgrade proposal 28

29. Summary We have four items and would like to get the consent of the DT: • Reinforcement of measurementsinSector 13 & 14 • Measurement of inter-wheeldistanceswithin Barrel • Additional PG targets/redesignPGtargetsonMABs • ProgrammingextensiontoBoardPCs • Use TDTin Ali reco Institutes could be involved: • ATOMKI • Budapest • Univ of Debrecen • CERN ? • Torino (Mimmo) • Aachen (TDT) Probably all of these modifications could be made in 2013. Barrel Alignment – Upgrade proposal 29