1. 1 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim MaPMT L0 Electronics & Photo detector mounts o Report from meeting –at CERN 22 May 2003 and follow-ups o L0 motherboard –Design completion scheduled for end 2003 –on critical path for MaPMTs o Photo detector mounts –RICH 2end of 2003 solution required which satisfies boundary conditions –RICH 1 more severe space constraints Conceptual Design

2. 2 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim 3 x 3 MaPMT Cluster Set-up 40 MHz Read-out APVm chip

3. 3 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Bleederboards

4. 4 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim MaPMT Module o Modules of 4x4 MaPMTs –16 tubes,1024 channels –Size: 113.8 x 113.8 mm 2 –Filling factor: 0.72 –Frame: carbon fibre, G10 –Cooling: 16 W / module o -metal shield –for individual tubes 0.9 mm thick o Lenses –incorporated in module –no optical contact o RICH system –# of modules: 232 –3504 MaPMTs –# of channels: 237 kc Proposal for photodetector choice / TDR

5. 5 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim LHCb RICH2 MaPMTs

6. 6 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Cooling o Power Dissipation –Bleeder board 0.55 W / resistor chain at HV = 1000 V –Power dissipation 8.8 W / module (MaPMTs) 2.2 W / module if 4 tubes share resistor chain –Beetle chip 750 to 900 mW or 6-7 mW / channel –Power consumption 7.2 W / module (8 Beetle chips) –Total power dissipation 16 W / module ~ 1000 W/ half plane –compare EUSO 200 W / plane need to understand this difference –Cockroft-Walton o Cooling design –needs input from L0 motherboard design Connections, Beetle pad layout

7. 7 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim RICH2 Photo Detector Plane o Proposal by Olav o Assumptions –basic unit for electronics 1024 channels, 8 Beetles, 16 tubes –From cooling simulations heat sink not more than 2 tubes wide o Modules of 8 x 2 MaPMTs –MaPMT pitch 28 mm –module width56 mm –module height224 mm o RICH 2 implementation –# of modules72 / half plane –# of MaPMTs1152 / half plane

8. 8 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Photo Detector Footprint o Assumptions –MaPMT pitch 28.45 mm (Olav used 28 mm) o RICH 2 half plane –photo detector area 1300 mm x 682 mm (RICH2 EDR) –6 columns with 11 modulesof 4x4 tubes, total 1056 MaPMTs 12 columns with 6 modules of 2x8 tubes, total 1152 MaPMTs o RICH 1 half plane –photo detector area 1200 mm x 540 mm (email Dave Websdale) –11 rows with 5 modules of 4x4 tubes, total 880 MaPMTs6 rows with 10 modules of 2x8 tubes, total 960 MaPMTs o Total RICH 1 and RICH 2 –# of MaPMTs with 4x4 modules3872 –# of MaPMTs with 8x2 modules4224 –less flexibility with 8x2 modules up to 9% more MaPMTs and electronics needed

9. 9 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Magnetic Shield/Lenses o -metal shield –for individual tubes –thickness: 0.9 mm increased B field in RICH 1 –not necessary in RICH 2 o Lenses –could be incorporated in magnetic shielding

10. 10 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Magnetic Shields o Magnetic Field Measurements –documented in note LHCb 2003-042 –requirement 10% maximum loss of photons –MaPMT needs shielding above 20 G longitudinal field –with -metal shielding can operate up to 80 G o RICH 2 –maximum B-field in box 4.1 … 9.1 G (RICH2 EDR) –about 5% loss of photo electrons at 10 G –safety factor >2 for <10% loss requirement – -metal shielding not required for RICH 2 o RICH 1 –see talk by Bill Cameron

11. 11 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Longitudinal B-Field -metal shielding: 0.9 mm thick 13 or 20 mm extension 13 0.9 MAPMT shielded MaPMT with 13 mm extension: MaPMT functions in longitudinal fields up to 8 mT (80 G) 90%

12. 12 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Lenses & -metal Design o Different mounting designs possible o Lenses / -metal mounted onto modules (Geoff Barber et al) –lenses glued to MaPMT or spring loaded – easy to exchange, little clearance needed – costs if lenses are not glued to MaPMT – lenses glued to MaPMT, transparency of glue o Lenses / -metal separate structure from modules –lenses or lens-arrays glued together – can be used as gas seal, cost savings, no more quartz window – cost savings, structure is glued – larger clearance wrt to MaPMTs, seal must be gas tight – cannot replace lens if it breaks or turns yellow o Lenses are separate structure from -metal – -metal can be part of modules – can combine advantages of above 2 designs – cost, complexity likely increases

13. 13 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Transparent Glue o EPO-TEK 301-2 –2 component epoxy –refractive index 1.564 –increased B field in RICH 1 –not necessary in RICH 2 o Transmission –> 97% from 300 nm.. 2.5 m o Needs study –Is EUSO using it?

14. 14 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Issues o Footprints of RICH2 and RICH2 –agree on dimensions for basic componentsurgent –4x4 vs 8x2 decisionwhen? o Magnetic Shields –RICH 2 no -metal shieldsok –RICH 1 Is -metal shield really neededwhen? –Lenses –study moulded lenses –agree on dimensions could be different for RICH 1 and RICH 2 when? –Decide if lenses make gas sealsoon o Photo detector mounts –decide on design of lenses / -metal when? o Next steps –Produce plan with decision points

15. 15 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Backup Slides

16. MaPMT L0 motherboard MaPMT meeting CERN 22 May 2004 Franz Muheim University of Edinburgh on behalf of MaPMT group

17. 17 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim L0 Interface Board 1 st prototype DACs PINT Power supply regulators GOLs VCSEL connectors to PIXEL chip TTCrx on reverse of board… JTAG connector

18. 18 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Reverse of L0 Interface Board 1 st prototype TTCrx TTC receiver chip

19. 19 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Transverse B-Field Transverse field in x-direction MaPMT insensitive to transverse fields up to 23mT (230 G) without shielding normalised light yield in whole MaPMT 90%

20. 20 MaPMT Workshop, Imperial College, 26/27 June 2003 F. Muheim Longitudinal B-Field Colour Legend 1 mT 2 mT 3 mT 4 mT 5 mT 6 mT 7 mT 8 mT 9 mT 10 mT 15 mT 20 mT 25 mT 30 mT 35 mT Conclusions: Agreement with previous test Top and bottom row drop first Sizable loss for edge rows at 3mT Decrease due to loss of p.e. Row 5 anomaly understood from x-talk in APVm readout No shielding light yield: rowslight yield: columns CoG: rowsCoG: columns R1 R5 R6 C1 C6 6mT