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Based on : Directors CD-2/3a Review of the BTeV Project (Sept. 28-30, 2004),

Mechanical Overview of BTEV RICH Detector Sub-Systems -- Design, Issues, Problems, Constraints, etc., etc., etc. …. The BTEV RICH Group M. Artuso, S. Blusk, C. Boulahouache, J. Butt, O. Dorjkhaidav, N. Menaa, R. Mountain ,

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Based on : Directors CD-2/3a Review of the BTeV Project (Sept. 28-30, 2004),

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  1. Mechanical Overview of BTEV RICH Detector Sub-Systems-- Design,Issues, Problems, Constraints, etc., etc., etc. … The BTEV RICH Group M. Artuso, S. Blusk, C. Boulahouache, J. Butt, O. Dorjkhaidav, N. Menaa, R. Mountain, H. Muramatsu, R. Nandakumar, R. Redjimi, T. Skwarnicki, S. Stone, R. Sia, J. Wang, H. Zhang Based on: DirectorsCD-2/3a Review of the BTeV Project (Sept. 28-30, 2004), by Herman Cease, FNAL

  2. Some Background • Background to current Mechanical Design • The present design represents work by us at Syracuse as well as the Fermilab engineering group, principally by Herman Cease. • First serious mechanical designs sometime around 1999. • It has gone through several iterations and changes as ideas and technologies used in the detector have changed. • Old aerogel was replaced by liquid radiator and 5000 PMTs • Photon detector changed from HPD to MAPMT as baseline • Other changes • Shakedown of design in beam test over the past summer. • I’ll describe the current mechanical design. • This represents a lot of work (so far). • But… • So… R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  3. For each of these Sub-systems: Describe the Current Design, Requirements and Issues… Mechanical Components of RICH Expansion Volume Mirror Tiles & Support Structure Tank Superstructure w/ Gas Fill PMT Arrays Liquid Vessel Beampipe (not shown) Beam MAPMT Arrays Front, Rear Windows (integrated) R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  4. Purpose 1. Basic frame on which all other components are mounted 2. Vessel for expensive heavy gas Critical Issues Must be strong and stiff Must maintain relative positions of mirrors and MAPMTs Must be leak-tight and light-tight Must have low density in central area Design Large, ~1000 cu.ft. internal volume Mostly 1” thick steel plate and beams Weight ~15,000 lbs Welded Construction Construction & Installation Plates fabricated at SU Tank assembled at C0 AH Tank Superstructure Tank Superstructure 3.5 m 5 m Beam 6 m R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  5. Purpose 1. Detects Cherenkov photons Critical Issues Must cover detector plane as completely as possible (close-packed) Dissipates power (in base), so creates heat load in an enclosed space Design ~9000 Vacuum tubes, run at 1 kV Size: 1x1 in2 face, ~1.5 in length Plug into base PCB, to distribute HV and route signal lines to electronics Construction & Installation Fabricated commercially (Hamamatsu) In this detector, will install MAPMTs as 2 arrays on a support in an enclosure (see following) MAPMTs & MAPMT Arrays MAPMTs = Multi-Anode Photo-Multiplier Tubes Electronics MAPMTs Base PCB (4x4) Concentrate on issues of relevance to the mechanical engineering R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  6. Purpose 1. Hold, support, shield MAPMTs 2. Support electronics, cables, cooling Critical Issues Must position MAPMTs in precise and stable manner in 2D array Must provide for close-packing of MAPMTs for max efficiency Must incorporate mag shields on MAPMTs Design Base PCBs mount to support Al channel and plate creates a “Row” Each row (module) supports 4x49 MAPMTs, with 23 rows/array Construction & Installation Fabricated at SU Installed in Enclosure (see following) MAPMT Support Electronics MAPMTs SIDE VIEW Base PCB Beam Test Prototype design shown (4x4x4 row) TOP VIEW R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  7. Purpose 1. Hold, support, shield MAPMT arrays 2. Create environmental gas volume Critical Issues Must have transparent window into main gas volume Must allow for removal of some subset of MAPMT array for necessary repairs Must shield interior to 10 G Must feedthrough all cables and lines Design Two separate enclosures Weight ~2000 lbs ea; Size: 2x1.5 m2 x 0.6 m Exterior steel plates as mag shielding Encloses: MAPMTs, support structure, electronics, cooling, cable runs, mag shields, etc. UVT Acrylic window Separate gas volumes MAPMT Enclosure MAPMT Enclosures R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  8. Construction & Installation Entirely constructed, assembled and tested at SU Shipped whole to FNAL (?) Mounted to superstructure in C0 CH Critique A few comments Not clear that it is possible yet to handle an entire row of MAPMTs for purpose of removal and repair Moving on pins is difficult mechanically Full cabling will be a nightmare Cooling interferes with this operation Need to precisely re-insert the row May require additional steel plates to provide adequate mag shielding In general, cooling and thermal issues insufficiently addressed Currently true for entire design, in my opinion Thermal expansion of various support members, as well as stability and motion MAPMT Enclosure (cont’d) REAR VIEW Beam Test Prototype design R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  9. Purpose 1. Part of RICH optics Critical Issues Must have low radiation length Must have high, stable reflectivity (not a mechanical issue) Design 16 individual mirror tiles ~7 m radius of curvature Weight: ~17 lb/tile Size: ~1x1 m2 each tile Two arrays: ~2x4 m2 each Construction & Installation Tiles fabricated commercially Mounts and support (see following) Mirror Tiles and Mirror Arrays Mirror Arrays Single Mirror Tile Mirror Support Structure R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  10. Prototype mounts have been made, tested, and successfully used in the beam test. (Although some issues remain…) Purpose 1. Mount mirror tiles on support structure 2. Allow adjustment of mirror angles for each tile individually Critical Issues Must have sufficient range of motion Must have sufficient precision of the movement Must be able to adjust tiles in situ Cannot sag or creep Design Three-point kinematic mounts Screw action for movement free/free, free/fixed, free/pivot Construction & Installation Tiles are mounted and pre-aligned on support structure Mirror Tile Mounts SIDE VIEW FRONT VIEW R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  11. Mirror Support Structure • Purpose 1. Mount mirror arrays to superstructure 2. Provide seal for gas vessel • Critical Issues • Must maintain relative positions of mirrors and MAPMTs • Must be insensitive to deflections in support structure due to loading or pressure/temp variations of gas • Must have low radiation length • Must capture beam pipe • Design • Weight: ~800 lb (tiles and frame) • Carbon fiber structure • Membrane for gas seal (also acts as the rear window of gas vessel) • Exterior fiducials for alignment PLAN SLICE 4.4m ELEVATION SLICE 4.4m 0.6m R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  12. Construction & Installation Mounted to the tank frame in C0 AH, using gasket-type seal Mirrors pre-aligned on structure Critique This Design: complicated CF support integrated with the structural frame CF tubes for access to adjustment of mirror tiles an integrated rear window Previous Design: two large panels hanging from a stiff frame tiles mounted to panels a separate rear window (Separate) Rear Window Design was always problematic Static pressure head of gas is large, so window bows under this load But can’t have braces in window region due to radiation length constraints Access to adjustment screws was cumbersome Beam pipe has to be sealed to windows with a bellows The mirror support is a mechanically complicated part of the design. Not really happy with any of these solutions Mirror Support Structure (cont’d) R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  13. Purpose 1. Hold, support, shield PMTs 2. Provide seal for gas vessel (?) Critical Issues Creates heat load Design ~5000 Normal PMTs (3.in diam) Four beehives of mu-metal mag shields, tilted at a single fixed angle Weight: ~3000 lb/beehive Injection-molded plastic holder for each PMT in mag shield tube Electronics, cables, cooling mounted to some interior frame Construction & Installation Fabricated, assembled, tested at SU Installation in PMT Enclosures (see following) PMTs & PMT Arrays PMT Arrays Support Holder R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  14. Purpose 1. Provide mag shield for PMTs 2. Provide seal for gas vessel (?) Critical Issues Open to main gas volume (no window) Size on bottom is constrained by floor Allow access to PMTs/electronics for repairs Must feedthrough all cables and lines Design Steel beam-and-plate enclosure Size: ~3x4 m2 x 0.3 m length Weight ~4000 lb each (fully instrumented) Encloses: PMTs, shields, support frame, electronics, cooling, cabling, etc. Construction & Installation Fabricated at SU Shipped whole to FNAL (?) Staged installation in C0 CH: (2008) Top enclosure installed first, allows for installation of the passive expansion volume; (2010) remaining three installed in C0 CH PMT Enclosures PMT Enclosures (4 total) R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  15. Purpose 1. Contain freon liquid 2. Provide seal for gas vessel Critical Issues Must have a transparent window Must restrict deflections due to hydrostatic head Must have low radiation length Must capture beam pipe Design Six Carbon Fiber and quartz vessels PVC support posts prevent quartz rupture Weight ~220 lb; Size: 2.5x2.5 m2 x 1.6 cm Gas seal to tank (also acts as the front window of gas vessel), w/ CF plate + flange Construction & Installation Fabricated at SU Two-piece assembly, attached in C0 AH Liquid Radiator Vessel Liquid Vessel 60 liter vessel FRONT VIEW R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  16. Beam Pipe • Purpose 1. Part of Fermilab accelerator • Critical Issues • Goes right through the middle • Must make gas seal to beam pipe • Cannot damage it during installation • Design • Beryllium vacuum beam pipe • Diameter: ~2 in • Bellows for gas seal, glued with rings to pipe • Construction & Installation • Exists already • Temporary Al pipe to be used • Inserted into frame at C0 AH (?) Beam Pipe R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  17. Purpose 1. Part of gas system 2. Allows for passive compensation of volume due to atmospheric pressure variations (simplifies gas system) Critical Issues Just Bad Design Ten 4 ft diam bellows each on own frame Construction & Installation Mounts on top PMT array in C0 AH Critique Used in beam test gas system Problematic, but “worked as expected” Bellows material leaks (expensive gas) Probably unreliable long term operation Solution: design pressure regulation into gas system (active gas system) Passive Expansion Volume WE HATE THIS THING !! (x10) Beam Test Prototype …THIS x 10 !! R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  18. HV Systems, LV Systems (electronics) MAPMT, PMT Gas System circulation, purification, monitoring Liquid System circulation, purification, monitoring Cooling (for Electronics) MAPMT (5300 W), PMT (1600 W) Mirror Position Monitoring LED Pulser System, Cal Pulser Systems All of these systems need gas-tight feedthru, routing paths, strain relief, etc. RICH Utility Subsystems ELECTRONICS COOLING LIQUID RADIATOR SYSTEM GAS RADIATOR SYSTEM R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  19. END • Extra Slides follow… R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  20. Rolling in the RICH Shutdown 2008 Gap is 144 inches ~ 30,000 lb, rolled-in weight ~ 40,000 lb, fully instrumented RICH Installation (1) R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

  21. INSTALLATION STEPS IN THE C0 ASSEMBLY HALL Shipping the tank frame segments to C-Zero; Assembling the tank frame by welding the walls together;  Attaching the liquid radiator vessel to the tank;  Mounting the front window to the frame;  Installing the mirrors and mirror support structure; Inserting the beam pipe into the tank; Making the beam pipe to window seals;  Mounting Top PMT enclosures completely instrumented;  Pre-aligning the mirror tiles; Install Gas Radiator Passive Expansion Volume; Initial gas leak check of the tank frame, window seals, and instrument enclosures. INSTALLATION STEPS IN THE C0 COLLISION HALL MAPMT Array Installation; Install Utility Plumbing and Control Systems; Fill the Liquid Radiator Vessel; Fill the Tank with radiator Gas; RICH Installation (2) R.Mountain, Mechanical Overview of BTEV RICH Sub-Systems, 22 Oct 2004

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