1. Front GEM Chambers Design concepts –Foils –Mechanics Electronics and DAQ Performance Current activity and plan Evaristo Cisbani / INFN-Rome Sanità group 2012 May 25 / A1n Meeting / JLabE. Cisbani1 People V. Bellinicoordination E. Cisbanimontecarlo, analysis, daq, test, coordination M. Capognidigitization, montecarlo, test S. Colillitech V. De Smetgas simulation, assembling procedure, test R. Fratonitech F. Giulianitech M. Griciatech F. Librizzitech M. Lucentinitech F. Mammolitianalysis S. Minutolielectronics P. Musicoelectronics, daq, test F. Notomechanics R. Perrinogas system, test G. Ruscicaanalysis F. Santaveneretech C. Suteraassembling, test Most of the material presented at the SBS meeting in Feb and May/2012

2. Chamber design Reqs and Guidelines Hit spatial resolution ~70  m Stand large background flux (~250 MHz/cm 2  and ~1/1000 charged particles) Active area  120x40 cm 2 Event acquistion rate ~20 kevt/s  Minimize R&D (follow COMPASS main design)  Reconfigurability (to some extend)  Reuse solutions for SBS rear tracker 2012 May 25 / A1n Meeting / JLabE. Cisbani2

3. SBS Tracker GEM Chambers configuration Chambers are made of smaller modules Electronics along the borders and behind the frame (at 90°) – cyan and blue in drawing Carbon fiber support frame around the chamber (cyan in drawing); dedicated to each chamber configuration Front Tracker Geometry x6 Back Trackers Geometry x(4+4) GEp(5) SBS 2012 May 25 / A1n Meeting / JLabE. Cisbani3

4. Foils 2012 May 25 / A1n Meeting / JLabE. Cisbani4 ---

5. Drfit, GEM and Readout foils 20 HV sectors on one side of the GEM 2012 May 25 / A1n Meeting / JLab E. Cisbani 5 40x50 cm 2 Large GEM module with small dead area Low material budget/Light Structure Modular design Flexible configuration Balanced weight

6. Improvements after first prototype Protection resistors on the border of the module frame (accessible) Balance strips capacity (larger strips are now the shortest, smaller are the longest) Replaced ZIF terminals (from 4 to 2 – more robust, easer to plug) Thanks to Kondo suggestions: –Added ring of grounding around the readout foil (connected to the front end card GND) –Corrected a trivial (but essential) bug in the readout layers order 2012 May 25 / A1n Meeting / JLabE. Cisbani6

7. Mechanics 2012 May 25 / A1n Meeting / JLabE. Cisbani7 Inner Frame Gas Flow Outer Service Frames

8. Inner Frame Permaglas, 8 mm width, 2 or 3 mm thick 21 slots for protection resistors 3 Gas In/ 3 Out-lets 10 Reference holes Internal spacers (3 vertical 2 horizontal) 2012 May 25 / A1n Meeting / JLabE. Cisbani8 F. Noto

9. Gas Flow / COMSOL MultiPhysics Simulation V. De Smet + F. Noto COMSOL/Thin-Film Flow Model Maximize uniformity and steady flux Minimize spacer apertures Final design 2012 May 25 / A1n Meeting / JLab E. Cisbani 9 Flow: 60 cm 3 /m = 2 Vol/h Pressure drop (Pa): Inlet:0.0590 Spacers:0.0015 Module:0.0462 Outlet:0.0575 Total:0.1642 (underestimated)

10. Gas / Current solutions under testing RILSAN pipe GEM 10 mm In  4 mm Out  6 mm In  4 mm  «Side» view Top view → No metallic parts Custom and commercial joints Commercial joints are rather large (13 mm!) Glued Permaglas IN or OUT SMC/KR 2012 May 25 / A1n Meeting / JLab E. Cisbani10 Pressure drop:  3.16 Pa/m Out  13 mm

11. 1 Assembling the first 40x50 cm2 module Stretching Gluing the next frame with spacers Foil Tension: T = 1 kg/cm Spacer Sector: S = 170 cm2 Expected maximum pressure on foil P  10 N/m2  Maximum foil deformation: u  0.0074 * P * S / T = 12  m Use stretching and spacers to keep foil flat Stretcher design from LNF / Bencivenni et al. 2012 May 25 / A1n Meeting / JLab E. Cisbani

12. 1212 Outer service frame 2012 May 25 / A1n Meeting / JLab E. Cisbani Mechanical support of: GEM modules Electronics (PCBs + cables) Additional services (gas system...) Carbon fiber Long bars made by 3 pieces Design is in progress First prototype beginning of summer FE cards between frame and backplanes F. Noto 1650 mm 780 mm

13. 1313 Service Frame / Detail 2012 May 25 / A1n Meeting / JLab E. Cisbani Reference pin as small mechanical support FE Cards Backplane Eye bold hole 23x100 mm 2 30x100 mm 2

14. 1414 Material Weight GEM Chamber Weight ModuleChamberUnit Weight Module Weight Chamber Weight ggg Frame Honeycomb13112,09224 336,27672 Frame GEM Gap3957,4832172,4496517,3488 Frame Drift1386,2248 258,6744 Frame Window2657,4832114,9664344,8992 GEM foil3935,704107,112321,336 Readout Foil1371,408 214,224 Drift Foil1324,952 74,856 Mylar Foil135,68 17,04 Electronics: FE185411,92214,56643,68 Electronics: Backplanes412150,74602,961808,88 Electronics: Patch Panels02150,740301,48 Elettronics: 3-meter HDMI-A cables82424019205760 FE-Backplane screws722161,5108324 Gas: 3 m pipes61843,3333333260780 Gas: Patch panel01301,480 Gas: Connectors6271060270 HV: cabling26100200600 HV: Voltage Divider13150,74 452,22 HV: Patch Panel01150,740 LV: 3m cables8241008002400 LV: Patch Panel01150,740 "Fascette" 38 mm502004,5225900 Screws010020200 Total (g)5236,15 17127,88 2012 May 25 / A1n Meeting / JLab E. Cisbani

15. 1515 Max deformation 2012 May 25 / A1n Meeting / JLab E. Cisbani New MaterialShort side (vertical)Long side (Horizontal) Carbon Fiber0.0040.081 Aluminium0.0180.330  Assume 20 kg of payload  Weight applyed in the center of the beam  Two points support mm

16. 1616 Electronics and DAQ 2012 May 25 / A1n Meeting / JLab E. Cisbani APV25 Front-End card Backplane MultiPurposeDigitizer (VME module)

17. 1717 Electronics Components GEM  FEC  MPD  DAQ Main features: Use analog readout APV25 chips 2 “active” components: Front-End card and VME64x custom module Copper cables between front-end and VME Optional backplane (user designed) acting as signal bus, electrical shielding, GND distributor and mechanical support 2D Readout 75 mm 49.5 mm 8 mm Up to 10m twisted, shielded copper cable (HDMI) Passive backplane (optional) 2012 May 25 / A1n Meeting / JLab E. Cisbani

18. 1818 Readout Electronics / FE v4 Front-end cards: first 25 samples of revision 4 under testing New connector: sligtly different connection scheme (middle spare pins are connected to ground) Old connectors 2012 May 25 / A1n Meeting / JLab E. Cisbani

19. 1919 Readout Electronics / MPD v4 Design of v4 under finalization –Move to HDMI type B only –Remove 2 Lemo connectors and USB (more space and firmware resources) –Add piggy back connector for future extension –Trigger sampling at maximum clock speed (240 MHz), time resolution expected at the level of few ns 2012 May 25 / A1n Meeting / JLab E. Cisbani

20. 2020 20 2012 May 25 / A1n Meeting / JLab E. Cisbani (128+12)x25 ns (2x128+7)x20 ns + VME64x spare readout FE  MPD transfer/processing time: ~9  s/sample APV long analog pipeline (>4 us): use second level trigger Zero suppressed data

21. 2121 DAQ Bus Interface Generic Model (virtual class) MPD Library Low Level I2C Trigger ADC Other High Level Initialize Configure Discovery Read Wrapper DB Module Structured text file for configuration Based on libconfig++ Main Implemented on C++ Run on Linux MPD as independent library One configuration file (text format) Use open source libconfig++ Self consistent output binary raw data DAQ Software 2012 May 25 / A1n Meeting / JLab E. Cisbani Analysis software: Based on C++/Root One geometry configuration file (text) Ingest raw data and fill a Root tree for further analysis Largely rewritten in the past few weeks Bug fixing in progress

22. 2 Some performance 2012 May 25 / A1n Meeting / JLab E. Cisbani Desy – Mainz Test beam

23. 2323 Beam test @ DESY / Full Module Size 40x50 cm 2 2012 May 25 / A1n Meeting / JLab E. Cisbani One 40x50 GEM module One 10x10 GEM chamber An ustrip Si telescope Small scintillators for trigger Low intensity electron beam 2-6 GeV (few KHz trigger rate)

24. 2424 Different event patterns We extracted «good events» and measured: Cluster charge, and x-y correlation and ratio Cluster size Noise (RMS) Selection Efficiency 2012 May 25 / A1n Meeting / JLab E. Cisbani Bad event Good event Standard processing: Hot channels masking Common noise suppression (median) Pedestal subtraction

25. 2525 Cluster charge, size and noise 2012 May 25 / A1n Meeting / JLab E. Cisbani Charge distribution and cluster size consistent with COMPASS data We do not expect dramatic difference respect to COMPASS

26. 2626 Charge correlation, beam spot and SNR Pretty good run (011) 2012 May 25 / A1n Meeting / JLab E. Cisbani ?

27. 2727 Noise (RMS pedestal) vs capacitance Progress since DESY/2010: better grounding, stable firmware 2012 May 25 / A1n Meeting / JLab E. Cisbani Runs differ for different GND connection

28. 2828 Latest Test under intense beam (Mainz/MAMI) 12-16/09/2011 2012 May 25 / A1n Meeting / JLab E. Cisbani

29. 2929 Online monitor / Mainz test Low beam current 2012 May 25 / A1n Meeting / JLab E. Cisbani Event x1 x2 x3 y2

30. 3030 Online monitor / Mainz test High beam current 2012 May 25 / A1n Meeting / JLab E. Cisbani See Vahe analysis report at SBS meeting x1 x2 x3 y2 Event

31. 3131 Real Experiment: Olympus, Feb/2012 From Jürgen Diefenbach The APV electronics has been installed on the Olympus 3xGEM tracker made of 6 10x10 chambers with 2D readout (pad/strip – about 2500 chs), operating in a magnetic field at the level of few kG. Two events with opposite magnet polarity; particles bend left o right in the x- histogram (Red triangles show hit candidates) 2012 May 25 / A1n Meeting / JLab E. Cisbani

32. 3232 Current activity and Plan 2012 May 25 / A1n Meeting / JLab E. Cisbani ----

33. 3 What we have 2012 May 25 / A1n Meeting / JLab E. Cisbani Electronics: All readout electronics ordered (order in standby); samples of the latest (final?) FE/backplane version produced Low Voltages and High Voltage power supplies in hands GEM and readout foils: About 1/3 ordered, only small part delivered About another 1/3 funded in 2012 Mechanics: All inner frames ordered, about ½ delivered Outer frame prototype ordered About 2/3 outer frames funded in 2012 Gas system: Mostly funded and procured Assembling: Everything ready (or under minor improvement)

34. 3434 Electronics and DAQ: –production and test –complete firmware implementation / improve software library –optmimize readout performance –(additional user: ATLAS group working on  MeGas prototype) Mechanics –finalize outer service frame design and produce first prototype HV –Final decision on HV divider to be taken Gas –Near chamber configuration to be finalized GEM modules –assembling and test (as soon as possible) Working on / Open activities 2012 May 25 / A1n Meeting / JLab E. Cisbani

35. 3535 As soon as possible: –When the readout foils will arrive (few days ?) start assembling the first 40x50 module (about 1 module/month-> 0.5 module/week) –latest FE electronics version release for 1 module (on hand) July-Sept. 2012: –test the module and electronics with rad. source; if fine aks CERN form production July 2012: –get outer service frame / electronics review at JLab (?) Sep 2012: –start mass productions of electronics Dec 2012: –1 st chamber completed (?) –Electronics available, ready for testing Dec 2013 (+2M): 4 chambers completed (?) Plan 2012 May 25 / A1n Meeting / JLab E. Cisbani