Detector R&D for Mu on Ch amber Anand K. Dubey For VECC group

1. Detector R&D for Muon Chamber Anand K. Dubey For VECC group

2. CBM Muon detector requirements: • Main issues: • The first plane(s) has a high density of tracks • -- detector should be able to cope up with • high rate. ~ 10 MHz/cm2 • good position resolution • Should be radiation resistant • Large area detector – modular arrangement • suitable options: • micropattern gas detectors such as GEMs, • Micromegas, and THGEMs.

3. MUCH R&D so far: we have assembled and tested double and triple GEM prototypes based on 10 cm x 10 cm GEM foils. Optimize the operating conditions with 10 cm x 10 cm. the detector should have: -- a high charged particle efficiency(>90%) -- a good dynamic range. -- a reasonable cluster size for tracking. -- a good rate handling capability In future we would like to go to 30 cm x 30 and later to foils with larger dimensions.

4. Schematic of prototype GEM chamber assembly CERN made GEM foils obtained from Area: 10cm x 10cm Readout PCB GEMS 1 2 3 Drift gap: ~7mm Induction gap: 1.5mm Transfer gap: 1mm Drift plane (inner side copper plated) In the next prototypes we have an O-ring on the perspex frame In order to facilitate quick changing on GEMs if needed. 12 x cm 12 cm x 10 mm

5. Testing of GEM chambers @GSI At the SIS 18 beam line using proton beams of 2.5 GeV/c Aim being : -- to test the response of the detector to charged particles. -- efficiency, cluster size, gain uniformity, rate capability -- testing with actual electronics for CBM : nXYTER -- testing with the actual DAQ -- Aug08-- first successful test with n-XYTER(with 64 channels bonded ) + GEM was performed. MIP spectra for 2GEMs and 3 GEMs were obtained. -- Aug-Sep 09, In 2009 a fuller version of nXYTER with all the 128 channels bonded was available. this offered a better configuration for efficiency estimation and also for cluster size estimation.

6. Readout Board for Test beam Aug-Sep 09 Two triple GEM chambers were fabricated : det 01 – with two different pad sizes(shown below) det02 -- same size pads but with larger induction gap Inside view Outside view Inside view

7. GEM chambers – Beamtest 2009

8. Aug-Sep09 test (with 2.3 GeV/c protons) pulse height spectra Correlation between GEM1 and GEM2

9. ADC distribution of main cell and variation with HV 4 fold increase in ADC for a deltaV(GEM) increase by 50V

10. Determining the Efficiency Time difference between trigger(aux) and GEM ROC Procedure: Get the GEM pads hit in 900-1200 nsec after last Aux. Offset + drift time Using STS Hits

11. Efficiency with time Eff_66 HV= 3650 HV= 3750 Looks like the detector takes some time to become stable, -- need more online investigations 95 % efficiency has been achieved by 3 GEM chamber used by the CMS upgrade group. The chamber tested in June2010.  next slide

12. 10 cm x 10 cm GEMs Readout: Strips of 0.8 mm pitch so 95 % efficiency is achievable things can be complicated with pads, -- one such large GEM with pad readout was tested in June 2010 -- analysis is still underway Preliminary Slides from Stefano Colaresi – CMS upgrade, RD51 miniweek, 19-07-2010

13. Cosmic Ray test setup at VECC • Setup for detector efficiency: • 1. Detector+Ortec preamp+amp • Using MANAS coupled to • PCI CFD card • 3. Using Aux + nXYTER

14. Results with MANAS GEM signal connected to Channel 56 of FEE (MANAS) Pedestal 64 channels for 4 MANAS No of triggers( from 3 FOLD) = 187 Entries =158 => 85% After pedestal subtraction -ADC of Channel 56

15. 3GEM Pulse height distribution at different HV with MANAS HV=3600 HV =3550 (Vgem=394 V) HV 3650 HV 3700 HV =3725(Vgem=413) The MIP peak shifts with HV

16. Top copper Readout PCBS for Test beam 2010 GND Plane Inner 2 GND Plane Top copper Inner 1 Pad area- 67*73 Sq mm For 3mm. For 4mm - 88*97 sq mm Bottom copper GND Plane • Main Features : • Both 3 and 4mm square pad sizes • Not Staggered (‘09 test beam module) • Symmetric Square Pads • Multi Layers ( 4) with GND Planes • Signal Tracks are distributed in 3 planes • Reduce the capacitance • Track to Track spacing increases • Reduce Cross talk • Blind Vias for gas integrity • Gnd Tracks between Signal Tracks Bottom copper Connectors for FEBs Connector with resistors

17. MuCh Layout

20. Placement of ROC Boards ROC stack ROC stack Tracking station plane 3mt (approx) 2m Physics With FAIR: Indian Perspective, Susanta K Pal

21. -- CMS upgrade, slides from A. Sharma, RD51 miniweek,19-07-2010 (1)

22. CMS Prototype GEM - Stack Profile ~ 15 mm (2)

23. CMS Prototype GEM - Test BoxLarge Drift Electrode Sample under test Jean-Paul Chatelain (3)

24. MUCH PCB design Top copper Inner 1 Inner-2 Bottom Copper • Modular Approach 2.6 mm square pads • Pads arranged in one block of 32*8=256. • Connected to 300 pin connector. • Tracks - shorter and not closer . • can be easily duplicated for bigger sizes. • 40 such FEE Boards for One Slat of 1mt. Length.. • Each block read by 1 FEB with 2/4 n-XYTERs ( 128/64 Channels) • FEBs can be mounted horizontal or vertical Blind vias (red ) to inner layer Blind vias from inner layers( blue) Physics With FAIR: Indian Perspective, Susanta K Pal

25. Conceptual sketch of Triple GEM chamber module 1 mt Gas out HV 10cm Gas in To be decided LV connector • Segmented LV power line/power plane on Detector PCB • each power line is feeding 5-FEBs • ground plane of LV line is in other layer of PCB 40 FEBs in one module in 1mt slat with about 10240 channels Physics With FAIR: Indian Perspective, Susanta K Pal

26. Chamber PCB 4 sq mm pads. 32*32 Array(1024 pads). PCB active area is 135mm *135 mm. Read by 2 chip FEB(256 channels) Basic block=32*8 array. Track lengths are short. Top side Inner 1 layer Bottom side GND Plane Inner 2 layer Sa SAMTEC-300 Pin connectors 2chipFEBs

27. Chamber PCB with 4 FEBs Bottom view of FEB FEB 2 FEB 3 FEB 1 FEB 4 Top view with 4 sq mm pads Bottom view –Connectors for FEBs

28. 2 CHIP FEB –PCB 8 layer PCB. Size =111mm*31mm No scooping for N XYTER on the PCB. Regulators - on top copper. Filter capacitors- on bottom copper N-XYTER ADC 300 Pin SAMTEC Connector ROC Connector Top Copper Bottom copper

29. SUMMARY • Double and Triple GEMs have been assembled at VECC. • Tests performed with radioactive sources as well with • proton beams at GSI. • Test with proton beams: Double GEM and triple GEMs • coupled to the first prototype of n-XYTER readout chip. • – preliminary response looked encouraging. • -- charged particle detection efficiency needs to be still higher. • investigations underway, using tests with cosmic rays. • Next test beam: two chambers of 3x3 sq. mm 4x4 sq. mm chamber • would require 8 FEBs. • Several layout s of the actual design of the Muon Chamber • under discussion. Actual size of large GEMs for the final chamber • under consideration –- keeping informed with the CMS upgrade • involving triple GEMs.

30. Thanks For Your Attention

31. BACKUPS

32. Readout plane-bottom Copper ERNI Part no 114805 4 No –68Pins 68 Pin connectors for FEB 1nXGen Resistors for input Protection 68 Pin connectors for FEB 1nXGen

33. Triple GEM: Test with Fe-55 3GEM: Gain vs. Vgem