Rich2 MAPMT Housing & Cooling Outdated designs and what is needed to get a final executive design

1. Rich2 MAPMT Housing & Cooling Outdated designs and what is needed to get a final executive design Imperial College – London , June 26 2003 M. Sannino for S. Cuneo - I.N.F.N. Genova

2. LHCb - RICH2 WITH MAPMT: support REMINDER: A PRELIMINARY STUDY HAS ALREADY BEEN DONE (LHCb 2000-005RICH) MAMPTs ARRANGED IN 2x2 CELLS HOUSING THE HV DIVIDER 2 LENSES OPTICAL ADAPATER INTEGRAL WITH MU-METAL SHIELD COLUMN ARRAY OF CELLS HOUSING 23 CELLS, WITH 6 mm DIA INTEGRAtED COOLING PIPE FOCAL PLANE ARRANGEMENT (12 COLUMNS) - OPTICAL ADAPTERS ARE ASSEMBLED IN A WINDOW M. Sannino for S. Cuneo - I.N.F.N. Genova

3. LHCb - RICH2:MAPMT support and lens mechanical design Electronic cards (green) Supporting frame • MAPMTs layout: • The groups of 4 MAPMTs will be installed on a vertical frame. Each frame will house 23 groups of 4 MAPMTs and a cooling pipe dia. 6 mm. The vertical frame will also house 2 electronics cards for each group of MAPMTs, that could be individually pull out from the back of the assembly. Cooling pipe H.V. divider 4 MAPMTs M. Sannino for S. Cuneo - I.N.F.N. Genova

4. LHCb - RICH2:MAPMT support and lens mechanical design Outer frame with 12 slots • MAPMTs layout: • Each vertical frame (with 22*4+2 MAPMTs, cooling pipe, 2 electronics cards) will be introduced in an outer frame, from which it could be individually pull out from the back of the assembly. The outer frame will have devices for adjustements in the X-Y-Z directions, and 12 groove slots, to house 12 vertical frames with 22*4+2 MAPMTs. Vertical (inner) frame with 22*4+2 MAPMTs M. Sannino for S. Cuneo - I.N.F.N. Genova

5. LHCb - RICH2 WITH MAPMT: support DEVELOPMENTS: THE MICRO-CELL CONCEPT HAVE BEEN DEVELOPED AND PROTOTYPED BY THE AIRWATCH/EUSO COLLABORATION GROUP IN GENOVA M. Sannino for S. Cuneo - I.N.F.N. Genova

6. LHCb - RICH2 WITH MAPMT: cooling MATERIAL: 5 mm THICK FR-4 WITH A 0.5 mm THICK COPPER LAYER HYPOTHESIS: 0.84 W (HALF POWER) ON THE DIVIDER, 10°C WALL TEMPERATURE NATURAL AIR DRAFT NOT CONSIDERED COOLING MEDIUM: COLD WATER @ 8.5°C WATER TEMP. DROP ALONG A COLUMN OF MAPMTS: 1°C COOLING PIPE INT./EXT. DIA: 5.5/6.0 mm PIPE MATERIAL: ALUMINIUM (WITH CONDUCTIVE GREASE OUTSIDE) OF THE OTHER COMPONENTS ESTIMATED WATER FLOW: 390 dm3/h PRESSURE DROP IN A COLUMN: 0.002 bar Wall temperature near the pipe (10°C) THE THERMAL POWER OF THE H.V. DIVIDER COULD BE FURTHER REDUCED THE COOLING SYSTEM WILL HAVE TO BE UPSIZED TO TAKE INTO ACCOUNT OF THE THERMAL CONTRIBUTION(PRESENTLY UNKNOWN) Hot spots: (39°C) M. Sannino for S. Cuneo - I.N.F.N. Genova

7. LHCb - RICH2 WITH MAPMT: lens/window FLAT MU-METAL BARS GLUED ONTO A METALLIC OR CARBON FIBRE SUPPORT EXTRUDED SQUARE MU-METAL PIPES, GLUED TOGETHER ON THEIR SIDES. THEY ALSO SUPPORT THE LENSES. POSITIONING PINS ALLOW A PRECISE GLUEING M. Sannino for S. Cuneo - I.N.F.N. Genova

8. LHCb - RICH2 WITH MAPMT: developments • TO PROCEED ON THE BASIS OF THE PRELIMINARY LAYOUT, WE NEED AT LEAST: • OPTICS (LENSES GLUED ON MAPMTs? LIGHT COLLECTORS? INDIVIDUAL OR GROUPED IN CELLS? WINDOW?) • MU-METAL SHIELDS (INDIVIDUAL OR GROUPED IN CELLS? MANUFACTURING TECHNOLOGY? • ELECTRONICS (CHIP ON THE DIVIDER PCB? KAPTONS? CONNECTORS& FLAT CABLES? LAYOUT OF THE FRONT-END CARDS?) • BETTER ESTIMATE OF THE POWER BUDGET • COOLING IN ITSELF SHOULDN’T BE A GREAT ISSUE • IN PRINCIPLE, THE OVERALL DIMENSIONS OF THE FS PANEL SHOULD BE THE SAME FOR BOTH DETECTORS (MAPMT OR HPD) • AS MAPMTs ARE COMMERCIAL ITEMS, THEIR GEOMETRY AND INTERFACES ARE ALREADY WELL DEFINED. THEN, THE INTEGRATION IN THE FOCAL SURFACE COULD PROCEED FASTER THAN WITH THE HPDs (PROVIDED THAT THE ABOVE LISTED PENDING POINTS HAVE BEEN FIXED) M. Sannino for S. Cuneo - I.N.F.N. Genova

9. After this presentation, last march Stefano made the following requirements in order to be able to start a sensible work: Subject: MAPMT cooling From: Stefano Cuneo <stefano.cuneo@ge.infn.it> Date: Thu, 20 Mar 2003 14:26:15 +0100 To: David Websdale <d.websdale@ic.ac.uk> CC: Olav ULLALAND <Olav.Ullaland@cern.ch>, Franz Muheim <muheim@ph.ed.ac.uk>, Mario Sannino <Mario.Sannino@ge.infn.it> Dear David, I argue, from Franz's minute of the meeting held on February 26th (that Mario forwarded me today), that some work is required to my group about cooling of focal detector plane. I think that the study I presented at RAL 3 years ago, and again last February, could be considered still valid for the L0 board, unless something new can appear. I remind you that solution foresees Kaptons or flat cables connecting L0 to L1 board, where the chips should be located. Then, on L0 boards the only electronical components are MAPMTs and condenser and resistors of the HV divider. A thermal study of L1 boards could be of some interest, provided that anybody could supply me enough information about shape, position of components and individual power dissipations. As far as today, I have no details at all to proceed. Best regards. -- ing. Stefano CUNEO Mech. Eng. Dpt. Head I.N.F.N. M. Sannino for S. Cuneo - I.N.F.N. Genova

10. Design Requirements and Consequent Timings After the last may 22 meeting at CERN and another meeting between Genoa people and Olav on last June 3 it turned out that a complete different layout (e.g. 2X8 or 4X4 MAPMT’s on the same board) from point of view of electronics is needed. In this new situation also the heat developed seems to be much higher than initially foreseen as both on the MAPMT basis PCB’s also the Beetle, with a larger heat dissipation, will be mounted and, as underlined by Franz in his presentation, also the L0 card will need to be cooled. Initially it was deemed that L0 cooling with forced air flow was enough but this does not seem appropriate any more. With these points in mind, in order to be able to start a sensible work that can become easily an executive design, as Stefano pointed up in the above mentioned meetings, one needs to know not only the power dissipated by the cards but also the position (at least roughly) where more heat is produced and so where it needs to be dissipated. This has a consequence on piping design and, as pipes are, at least in part, integrated in supporting frames it has a consequence on the whole design. As a consequence of what above described we must face a practically complete new design and not a simple review of old design of 3 / 4 years ago. In such a situation Stefano estimates a development time of 6 months i.e. to have a complete executive design by the end of 2003 all these data should be known now!! M. Sannino for S. Cuneo - I.N.F.N. Genova