Nilanga Liyanage University of Virginia UVa GEM Team

1. GEM Chambers for the Polarimeter Trackers Nilanga Liyanage University of Virginia UVa GEM Team Dr. Kondo Gnanvo, Dr. Vladimir Nelyubin, KiadtisakSaenboonruang, Chao Gu, XinzhanBai, Jie Liu, Seth Schcher, Taylor Scholz

2. SuperBigbite GEM Trackers Front Tracker Geometry 18 modules In Italy x6 • 50 cm x 40 cm and 50 cm x 50 cm Modules are assembled to form larger chambers with different sizes • Front tracker: Six 40 cm x 150 cm GEM layers • built in Italy – INFN • Polarimeter trackers: Eight 50 cm x 200 cm GEM layers • to be built in Virginia 40 modules At UVa GEM module production starting now Total Area ~ 16 m2

3. New design for the SBS GEMmodules for polarimeter trackers by Kondo Gnanvo Need 32 modules + 8 spares 4 GEMs with APV25-front end for card seach of the 8 Polarimeter chambers

4. Progress so far • Setup and instrumented the GEM lab • Constructed two 40 cm x 50 cm prototypes based in the Rome design • First chamber under testing now. • Kondo finalized the new design based on lessons learned.

5. UVa GEM Lab • Our Class 1000 Clean Room (3.5 × 3 m2 ) • Built originally for the BigBite drift chambers construction • Located in a large (4.5 mx 9 m) semi-clean area. • Additional clean room to be added later this year • Mechanical stretching device • HV Test N2 Gas box • KeithleyPicoammeter 6487 with 500 V source Ohmmeter • Ultrasonic bath (Elmasonic S900H ) • APV25 based readout systems with 5000 channels for testing GEMs • Wiener MPOD High Voltage system Storage Shelves Display Monitor N2HV Test Box Stretching Device Storage Cabinet Pico-ammeter Ultrasonic bath

6. UVa GEM Lab • Mechanical stretching device • HV Test N2 Gas box • KeithleyPicoammeter 6487 with 500 V source Ohmmeter • Ultrasonic bath (Elmasonic S900H ) • APV25 based readout systems with 5000 channels for testing GEMs • Wiener MPOD High Voltage system Our Class 1000 Clean Room (3.5 × 3 m2 ) Built originally for the BigBite drift chambers construction Storage Shelves Display Monitor N2HV Test Box Stretching Device Storage Cabinet Pico-ammeter Ultrasonic bath

7. Assembly Steps of the SBS GEM Prototype at UVa Resistors soldered on GEM N2 Box for HV test of GEM Foils

9. Assembly Steps of the SBS GEM Prototype at UVa Preparation of the readout board Stretching of GEM foils

10. Test framesglued

11. First results from SBS GEM Prototype: MPD readout X-axis t1 X-axis, t1 + 25 ns Y-axis t1 Y-axis t1 + 25 ns

12. First results from SBS GEM Prototype: SRS readout Distribution of the mean ADC count: Gain uniformity Y-axis (mm) X-axis (mm) X/Y (ADC) = 1.12

13. First results from SBS GEM Prototype: SRS readout Distribution of the mean ADC count: Gain uniformity Y-axis (mm) X-axis (mm) X/Y (ADC) = 1.12

14. Cosmic test results – from 10 cm x 10 cm chamber

15. SBS GEM Chamber Gain Calibration

16. APV 25 Gain Calibration Pulse generator 360 mV Attenuator 3db to 39 db Capacitor box 3.3 pF GEM chamber readout 50 m Signal form one strip External trigger APV25 Electronics (MPD and SRS) • Test pulse = 360 mV, Capacitor = 3.3 pF  Equivalent charges = 7.2 Million e- • Injected charges = Equivalent charges / Attenuator  attenuation 3dB to 39 db Just did this calibration for both SRS and MPD systems

17. Pedestal Noise – RMS distribution for 128 stripes ADC chan.

18. New design for the SBS GEM polarimeter trackers –from Kondo Gas outlet • Module of 50x50cm2 to replace the 40x50cm2 • 32 modules to be built instead of 40 for the 8 Polarimeter chambers • Wider GEM frames along x-axis • Width of 30 mm instead of 8 mm • Better stretching • alignment holes away from active area • Wider readout support frame along x-axis (74 mm) • Room for strips connectors and GEM HV sectors electrodes • No protective resistors on the GEM foils • External resistor boards • Gas system same as in Evaristo design Gas inlet window Drift cathode GEM foil 1 GEM foil 2 GEM foil 3

19. GEM Foil with HV sectors Alignment holes 12 HV sector electrodes 562 mm 562 mm gas holes 600 mm 590 mm

20. GEM Frame with outer frame 528 mm 572 mm 562 mm 562 mm 512 mm 512 mm 572 mm

21. GEM Frame without outer frame after assembly 528 mm 512 mm 512 mm 572 mm

22. GEM Foil with HV sectors

23. GEM Foil with HV sectors after assembly 600 mm 528 mm

24. GEM Foil with HV sectors on its frame after assembly

25. Readout Support with its outer frame 10 mm 100 mm 245 mm 572 mm 528 mm 562 mm 562 mm 245 mm 10 mm 100 mm Up to 660 mm to be decided with Rui

26. Readout Support with its outer frame

27. Keeping the outer frame during assembly Fixation holes Alignment holes

28. Readout support after assembly 528 mm Up to 660 mm to be decided with Rui

29. X/Y readout board with Panasonic connectors and Italian APV25 based electronics Y-Strips connectors on flexible PCB Y-Strips connectors on flexible PCB APV-25 FE cards (Italian Electronics) on scale on the readout board Panasonic connectors 49.5 mm 80 mm

30. SBS GEM with APV25 FE cards (Italian Electronics)

31. Frame Design

32. 4 SBS GEMs with APV25-FE for each of the 8 Polarimeter chambers

33. Future plans • Install new clean room and upgrade equipment. • Parts for two 50 cm x 50 cm prototypes ordered – expect delivery by December. • Complete the construction of prototypes by February. • March to May 2013. • Characterize the chambers, finalize the design and order parts for 8 (?) chambers. • Order Electronics for 8 chambers • Proposed production schedule • May 2013 – May 2014 – 8 modules • May 2014 – May 2015 – 16 modules • May 2015 – May 2016 – 16 modules • It is crucial that we get our GEM foil orders out as soon possible.

34. Cosmic test results