Thomas Jefferson National Accelerator Facility Page 1 CD Workshop Dec 2-3, 2009 CLAS12 Central Detector Overview and Integration David Kashy Hall B Lead Engineer CLAS CD Workshop Saclay December 2-3, 2009

Thomas Jefferson National Accelerator Facility Page 2 CD Workshop Dec 2-3, 2009 Outline System Overview Solenoid and Support HTCC and Moeller Shields CTOF and Support SVT and support Summary/Conclusion

Thomas Jefferson National Accelerator Facility Page 3 CD Workshop Dec 2-3, 2009 Hall B Overview Hall B Space Frame Hall B – 98’ Diameter 20 Ton Polar Crane Beam entry tunnel Beam dump tunnel Cryogenic Supply and Return Line

Thomas Jefferson National Accelerator Facility Page 4 CD Workshop Dec 2-3, 2009 CLAS12 Detectors Silicon Vertex Tracker Central Time of Flight Solenoid High Threshold Cerenkov 3 Regions of Drift Chambers Torus 3 Panels of Time of Flight – 1a & 2 reused from CLAS Low Threshold Cerenkov – Reused from CLAS Electromagnetic Calorimeter – Reused from CLAS Pre-Shower Calorimeter

Thomas Jefferson National Accelerator Facility Page 5 CD Workshop Dec 2-3, 2009 Solenoid Purposes are: – Central field for tracking – Provide magnetic shielding of Moeller Electrons Peak field 5T Homogeneous central region 1e-4 in Ø =25mm L = 40mm Limited fringe field at locations of High Threshold Cerenkov PMT’s Contract awarded to Wang NMR 11/20/2009 Solenoid supported by 3 legged cart. Solenoid Lead can and Cryo reservoir Magnet Cryostat

Thomas Jefferson National Accelerator Facility Page 6 CD Workshop Dec 2-3, 2009 Central Detectors Central tracker and Time-of-Flight detectors are attached directly to the solenoid. This provides stable reliable support that will limit external vibrations since its mass is very large ~20tonn

Thomas Jefferson National Accelerator Facility Page 7 CD Workshop Dec 2-3, 2009 Plans for Mounting to Solenoid SVT Mounts CTOF Mounts Solenoid attachment to cart Solenoid specification shows desired mounting to be at ends of magnet. Details will need to be worked out with Vendor CTOF will be mounted from both ends Central Tracking Detectors must be mounted from upstream end only or we will loose HTCC and CLAS12 acceptance

Thomas Jefferson National Accelerator Facility Page 8 CD Workshop Dec 2-3, 2009 High Threshold Cerenkov Counter HTCC surrounds the solenoid and CD from outside It also protrudes inside with close clearance to the CTOF and also FST or other central tracker Several Moeller Electron Shields are planned They are envisioned to be cantilevered off the Torus Materials to be Lead or Tungsten or a combination Different configurations depending on the type of run (rastered or normal beam) High Threshold Cerenkov Outer cone- very close to light guides

Thomas Jefferson National Accelerator Facility Page 9 CD Workshop Dec 2-3, 2009 Central Detector Section View CTOF – ID = 500mm – OD = 563 mm HTCC starts at 380mm (desired to start earlier) Moeller Shield fits very closely to inside cone of HTCC High Threshold Cerenkov Outer cone- very close to light guides Moeller Shield

Thomas Jefferson National Accelerator Facility Page 10 CD Workshop Dec 2-3, 2009 Solenoid and Central Tracker SVT/Central Tracker supported off the Solenoid upstream Flange 6 link support system is the current design

Thomas Jefferson National Accelerator Facility Page 11 CD Workshop Dec 2-3, 2009 Latest Central Tracker Layout Two size BST stave assemblies Target size limited to 3” OD Considering removable R1 BST to allow HD Ice target Max radius of Central Tracker 238mm Note the HTCC starts at 380 mm so there is some room for Micro Megas

Thomas Jefferson National Accelerator Facility Page 12 CD Workshop Dec 2-3, 2009 Silicon Vertex Tracker Cold plate with brass inserts Stave support Stave Cooling analysis shows efficient heat removal Deflection analysis complete Assembly and alignment methods will be confirmed with region 1 barrel assembly Documentation and tech notes at

Thomas Jefferson National Accelerator Facility Page 13 CD Workshop Dec 2-3, 2009 Latest Stave Design Copper/Aluminum Nitride FR4 Silicon 3 places FR4 Copper Rohacell Many designs considered Latest design uses Silicon Wafer as structure as well as detector, (proposed by M. Merkin and analyzed by S. Mandal) Prototype cores formed at JLab in mold First results give core thickness 2.78mm +/ mm, with higher quality mold we expect better

Thomas Jefferson National Accelerator Facility Page 14 CD Workshop Dec 2-3, 2009 SVT Engineering Results ItemUnitsValue Coolant temperature C15 Peak temperatureC22.1 Maximum deflection Microns10 fixed-pinned (R3&4) R2 BST thermal analysis Max. Deflection ~10.5  m R3&R4 BST deflection analysis Max. Temp ~22.1 C

Thomas Jefferson National Accelerator Facility Page 15 CD Workshop Dec 2-3, 2009 CTOF There have been two parallel design efforts One with standard PMT’s and one with high magnetic field PMT’s decision on which one is pending more study on HF PMT design

Thomas Jefferson National Accelerator Facility Page 16 CD Workshop Dec 2-3, 2009 Solenoid and CTOF CTOF is supported from both the upstream and downstream flanges of the solenoid Room for Central calorimeter or Neutron detector is being left for future upgrade

Thomas Jefferson National Accelerator Facility Page 17 CD Workshop Dec 2-3, 2009 Installation of Counter Assembly Reference (conservative) design shown here Counters will be built and tested complete – Light guides glued to scintillator – Wrapped and light sealed – PMT’s and 2 of the 3 layers of shield pre-installed Individual counter assemblies will be installed one at a time A strong-back will support the counters to prevent bending and glue joint failure Installation fixture will clock the light guide assembly to the proper Φ angle Counter exploded view Strong Back

Thomas Jefferson National Accelerator Facility Page 18 CD Workshop Dec 2-3, 2009 Counter Assembly Installed Installation fixture will roll counter assembly into position through the Solenoid bore Light guide assembly will be mounted to permanent clamps, then strong-back clamps can be removed

Thomas Jefferson National Accelerator Facility Page 19 CD Workshop Dec 2-3, 2009 Beam Line Most Beam Line Devices reused from CLAS – Steering, focusing and raster magnets – Beam Profile Monitors and Beam Position Monitors – Cryogenic Target – Photon Devices will be left on beam line including Photon Tagger, radiators, collimators and pair spectrometer Shielding after target simulated and defined through the Torus Re-arrangement of Moeller measurement system components, a study optimizing this is underway Shielding Cryogenic Target and Cart BPM’s (2) Raster Magnets (2 pairs) Tagger Magnet and other Photon Devices

Thomas Jefferson National Accelerator Facility Page 20 CD Workshop Dec 2-3, 2009 Hall B Prepared for CLAS12 Installation Forward Carriage with Electromagnetic Calorimeters Space Frame Cleared of Beam Line equipment

Thomas Jefferson National Accelerator Facility Page 21 CD Workshop Dec 2-3, 2009 CLAS12 installation schedule

Thomas Jefferson National Accelerator Facility Page 22 CD Workshop Dec 2-3, 2009 CD installation An additional level will be added to the space frame for the CD and HTCC Torus will be installed next The Solenoid will be craned in CTOF will be installed after solenoid acceptance testing Central Tracker is installed last

Thomas Jefferson National Accelerator Facility Page 23 CD Workshop Dec 2-3, 2009 Torus Assembled and Central Detector added Solenoid and Central Detector - slides on rails into the space frame for maintenance Torus positioned and aligned Space frame addition for Central Detector and HTCC

Thomas Jefferson National Accelerator Facility Page 24 CD Workshop Dec 2-3, 2009 Safety To work in Hall B all persons must be Trained and Qualified All work in Hall B work is scheduled and reviewed by the Hall Work Coordinator Independent activities have been and will continue to be reviewed for space and resource interferences Stop Work Program will always apply ISM principles must be followed Lock Tag and Try/LOTO will be used Tested and Inspected lifting fixtures PPE will be worn as required Hall B is a low radiation environment this will allow most items to be removed from the hall after survey w/o delay.

Thomas Jefferson National Accelerator Facility Page 25 CD Workshop Dec 2-3, 2009 Summary Design of CTOF and SVT proceeding Will be working with Solenoid vendor on supports for CD Looking forward to contributions on Central Detector Planning for installation being integrated in the design phase

Thomas Jefferson National Accelerator Facility Page 26 CD Workshop Dec 2-3, 2009 CLAS12 is COMPLETE!