1. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 1 1 BCAL Construction & Readout Update Contributions by: SiPMs: K. Janzen, A. Semenov, C. Zorn, F. Barbosa, SensL Simulations: S. Katsganis

2. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 2 2 Overview BCAL Construction –Start in Spring ‘09? SiPM Progress –JLab, Regina, SensL: meetings, reports –Performance: PDE, DR, array assembly Alternative Readout Simulation Issues

3. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 3 3 Construction - Two Modules (two presses)

4. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 4 4 Construction - Four Modules (four in a shipment)

5. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 5 5 Construction Logistics Total calendar days for delivery of 49 modules: 817 days from D-0. Project Coordination –Base Crew: undergraduates –Construction Manager: one person, full time over the entire construction period; will be trained in construction techniques and will be responsible for day-to-day supervision and QA of the matrix build, as well as crew contacting and scheduling, and reporting. Draft ad exists. –Training: Regina faculty and staff will do the initial training of the construction crew and the Construction Manger (CM). From then on, the CM will take over this task for the subsequent crews with assistance from Regina, during carefully timed trips of the latter to Edmonton. –Chief Machinist: Gilbert Lachat (UofA/CPP) –Supervising Engineer: Jan Soukup (UofA/CPP) Oct. 15 visit to U of Alberta: Elke, Elton, Tim, George, Zisis

6. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 6 6 BCAL Readout Considerations Technical specifications: outlined in GlueX-doc-795-v17 –SiPM tests are underway; past/ recent results of tests of fine mesh PMTs Geometry: especially related to acceptance gap between BCAL and FCAL –Light guides and inactive material is different for the two options. We need to simulate the effect of each –Precise configuration of light guides for FM PMTs on the upstream end, where the field at the end of the BCAL exceeds 0.5 T –Detail description of cables and electronics on each detector Granularity: optimization of distribution between inner and outer detectors –Which detectors should have discriminators and TDCs –Study of signal splitting, choice of discriminator; this has an impact on no of cables Resolution: Complete simulation studies for correct thresholds for the FM –Studies of timing resolution. Realistic simulation for both photons & charged particles –Resolution for various geometry options (mentioned above)

7. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 7 7 Roadmap SensL is not meeting our PDE  DR requirement Schedule delay: 3-4 months Contract extended Sept 22 decision for array cell type Contract Start

8. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 8 8 Targets & Device Details Devices: –SPMMicro –SPMArray –SPMPlus Processes: –Trenching –Gettering –Electronics SPMMicro Test Samples @JLab (+ 2 @Regina) (GlueX-doc-795-v17) A20HD (3 samples) - 1 mm^2 - (circular pi/4 mm^2 area)- Getter 2 - 848 microcells - FF = 43% A35HD (3 samples) - 1 mm^2 (circular) - Getter 2 - 400microcells - FF = 59% A20HD (3 samples) - 3x3 mm^2 (square 2.85 x 2.85 mm^2)- Getter 1 - 8640 microcells - FF = 43% A35HD (3 samples) - 3x3 mm^2 (square) - Getter 2 - 3640 microcells - FF = 59% A35HD (3 samples - 1 defective) - 3x3 mm^2 (square) - Getter 1- 3640 microcells - FF = 59% No trenching

9. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 9 9 Gettering - PDE/DR effect (SensL, C. Zorn) (No Getter) (Getter #1) (Getter #2) (No Getter) (Getter #1) (Getter #2) Gettering process drives DC reduction –Weaker effect on edge intensive device (20um) –Minimal DC reduction going from Getter #1 to Getter #2 processing for A20H device. PDE reduction significant with the introduction of Gettering (more than originally anticipated). Closet Device to specifications: –A35H Getter #1 process: 13.5% PDE and 8MHz DC per SPM.

10. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 10 Specification: PDE vs Dark Rate Design Goal (fixed resolution) (0.12, 42) (GlueX-doc-795-v17) 13/16 Scaled by x16 20% sampfrac

11. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 11 Electronics and Timing SPMPlus TIA Boards, labeled 080723 #2 and #3. –Frequency response, transient simulation, pulse response –Optimization of the rise time and gain possible once final sensors are available and input capacitance is fully characterized. –SPMPlus electronics boards are well behaved and exhibit very low output offset voltage. Baseline shift Noise at different frequencies 2nd pulse (GlueX-doc-1024) 11 ns rise time -200 V offset no abnormalities in tail

12. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 12 SPMMicro: Performance + 20 C May Sept

13. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 13 SPMMicro: DR & Cross Talk Correct by 13/16 Extrapolated x16 May Sept

14. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 14 SPMMicro: 90 Sr Devices tested: –1-mm 2 A20HD/A35HD, 9-mm 2 A20HD IV scans: Vbr origin slight diffs 90 Sr source + green fiber tests: –good rise and fall times; –level shift, no second pulse, lots of noise in the analog pulses, pedestal resolution from SPM Results: –Nice p.e. peaks at diff overbias –Good linearity; p.e. lines intercept at +0.85 V –Good linearity also on plot versus no. of p.e. for different overbias curves (GlueX-doc-1066)

15. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 15 SPMPlus: Assembly Issues Setup: laser, fiber, SMA connector, green fiber, 1mm collimator, x-y stage, scope Laser at 2.5MHz, 60ps pulse Over-bias: +2V (at 28.3 V) 10 ns rise, 70 ns decay Uniformity improved (8 cells within 10%, 12 within 20%) (GlueX-doc-1024) Type 1: Low Gain Output /Good Timing –This pixel behaviour results in as much as 2x reduction in optical output over normal pixels. –Problem corrected by optical binning procedure. Type 2: Dead Channels –50% yield on early assemblies based on electrical IV measurements. –Root cause was with subcontractor process where poor metal adhesion was identified due to insufficient adhesion layer resulting in delamination of the metal from the glass. –Latest builds (Build ID: 080408_1_10) have shown 100% yields on a batch of 10 array builds (i.e. all 160 channels fully functional). No type 2 defect observed indicating that new adhesion process has fixed the fail mode. Pixel Failures Wafer Selection

16. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 16 SPMPlus: No. of p.e. - summary TestSetupNo of p.e./MeV (@module end with cell size correction) Comments Hall-B cosmicsXP2020+ blue fibers4-5Mod-1, 3.8 cm readout Regina cosmicsBurle 8575+blue fibers4Mod-2, 3.8 cm readout Regina cosmicsEMI + green fibers3Mod-2, 2 cm readout Regina cosmicsSiPMPlus + green fibers4.6 (maybe 5.3 if all cells worked) Mod-2, 2 cm readout Regina 90 SrA20HD+ green fiber7.5 (x2x0.15MeV=~2pe) Single fiber (GlueX-doc-1069 and 1066) (see Beni’s talk (doc-1106) for new results - 90 Sr+fiber)

17. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 17 Thinner Lead Sheets? Objectives –increase sampling fraction –  lower threshold and relax demand on PDE GEANT3 simulations with new geometry; they agree with FLUKA 2006.3b Glue 0.26mm  0.5mm Pb 0.20mm  0.2mm Pb 0.20mm Rear+sides 1.0mm Pb 0.2mm Pb KLOE samples nominal candidate? nominal candidate? Clad

18. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 18 In a nutshell… A20HD SPMMicro has yielded PDE of ~6%- 9% in the +1.5V to +3V range, consistent with SensL’s numbers A35HD 3x3mm 2 extrapolated/measured ~12-13%, DR ~ 80-90 MHz SPMPlus: no. of p.e. consistent with PMTs with blue and green fibers Significant improvement in Si wafer selection: optical binning Significant array manufacturing improvement: no delamination Progress is promising, but we need SPMMicro A35H PDE >12% and DR<40MHz, plus fully functioning SPMPlus arrays Upcoming decision: base cell for SPMPlus arrays But, we are not out of the woods…so, look at Plan B

19. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 19 BCAL Alternative Readout Comparison standard and alternative readout alternative readout based on fine mesh Hamamatsu PMTs:  New segmentation: inner (2 x (3x3) channel) 1” FM-PMT outer remains (2 x (2x2) channel) 1.5” FM-PMT outer remains (2 x (2x2) channel) 1.5” FM-PMTperformance  operate in magnetic field up to 0.5 Tesla upstream B-field > 0.5T upstream B-field > 0.5T increase light guide from increase light guide from 10 cm to 55 cm 10 cm to 55 cm (Courtesy of Elke) Disadvantage: Disadvantage:  Cost increase by ~350k$

20. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 20 Concepts for FM PMT housing

21. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 21 Light configuration studies

22. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 22

23. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 23 Simulation studies needed Resolution comparison: 6x4 vs 3x3 segmentation Improved simulation of resolutions –Include realistic threshold for FM option –Studies of timing resolution Study impact of inactive material at the end of BCAL on acceptance –Inactive material includes light guides, light detector, cables, dark box or cover, etc. –Comparison between SiPM and FM options –How many (which) changes in geometry should be studied? (see Blake’s talk (doc-1101) for newest results)

24. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 24 Backup Slides

25. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 25 Carl’s Setups NN  PDE Getter

26. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 26 Gettering Tests

27. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 27 A20HD 9mm 2 measurements are robust; extrapolate to A35HD 9mm 2 PDE. A35HD has better resolution. PDE under identical geometries and illumination conditions: PDE 1mmA35HD /PDE 1mmA20HD =1.35 SPMMicro: A35HD vs A20HD 1mm 2 PDE 9mmA35HD =1.35*PDE 9mmA20HD =~12  Carl: ~13% Solid angle effect projected

28. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 28 SPMMicro: Laser Kathryn’s details… (Regina June 30 Report)

29. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 29 SPMPlus: No. of p.e. - setup (GlueX-doc-1069)

30. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 30 Layout of fine mesh pmts

31. Z. Papandreou & E. Smith GlueX Collaboration Meeting, Sep. 19/2008 31 mechanically not possible nominal design alternative design BCAL Readout Possibilities