1. Overview of 35ton Phase 2 Detector Bo Yu yu@bnl.gov 35t Installation Readiness Review August 25, 2014

2. 2 35ton TPC System Overview 35t Installation Readiness Review – Aug. 25, 2014 Long drift CPA HV Feedthrough APAs Photon detectors Field cage Short drift CPA Cold electronics External cosmic ray counters on top and sides of the cryostat to provide through muon triggers.

3. 3 Key Detector Parameters Active volume: –Height: 1.96m, width:1.54m, drift length 2.2m, 0.26m; Active mass: 10 tonnes –4 APAs, 512 sense wires/channels per APA Each APA has: 224 X & G wires @ 4.5mm pitch, 144 U wires @ 4.9mm pitch, 144 V wires at 5.0mm pitch. Wire plane spacing 4.8mm. Each APA has 4 sets of front end mother boards (FEMB) @ 128 ch each. 3 unit tall: 50.4cm x 84cm active area (1PD) 4 unit tall: 50.4cm x 112cm active area (1PD) 7 unit tall (x2): 50.4cm x 196cm active area (3PDs each) –8 photon detectors of 3 different designs –Vertical gaps: 17mm; horizontal gap: 29mm –Field cage offset: 2cm from active volume Clearances –Bottom: CPA to floor: 25cm, FCA to floor: 31cm –Top: CPA to cryostat ceiling: 33cm, CPA to liquid surface: 19cm –E/S/W/N clearances: 25cm/?/52cm/20cm 35t Installation Readiness Review – Aug. 25, 2014

4. 4 TPC Design Features 35t Installation Readiness Review – Aug. 25, 2014 All components must pass through a 29.5” manhole Two drift volumes: –Asymmetric drift length: 220cm and 25cm. This allows the studies of double sided APA readout and a relatively long drift within the limited available space. HV Feedthrough –New design with flared shield to minimize electric field. Current limiting resistor built in (warm side of) the feedthrough. Corona detection circuit implemented in the HV filter. TPC Support –The cryostat was not designed to take load on the ceiling, so the TPC is standing on the cryostat floor In Vessel Video Cameras –Multiple video cameras are planned to be installed in the cryostat to monitor TPC HV components in case of HV discharges (9378).

5. 5 TPC Design Features: APAs 35t Installation Readiness Review – Aug. 25, 2014 4 APAs to test APA horizontal and vertical interconnect features, and to study detector response at the horizontal and vertical gaps between APAs Wire wrapping angle based on the LBNE conceptual design: ±45° on the induction planes with small delta angles to break symmetry 8 embedded PDs with 3 different designs One APA does not have the grounded shielding mesh One long APA does not have intermediate wire support so long wire (2m) behavior can be studied All FEE boards on an APA are enclosed in a Faraday cage which also serves as containment for gas argon boil off from the electronics

6. 6 TPC Design Features: CPAs 35t Installation Readiness Review – Aug. 25, 2014 Two CPAs, one with HV receptacle. Bias from the short drift CPA tapped from the field cage Solid stainless steel cathode surfaces with rectangular frames to study local drift field non- uniformity in larger FD CPAs 2” OD tubular outer edges to minimize electric field 5 Fiber optic diffusors are mounted on the long drift CPA to provide calibration light pulses to the PDs (not shown)

7. 7 TPC Design Features: Field Cage 35t Installation Readiness Review – Aug. 25, 2014 FR4 printed circuit board based construction. All Edges of the copper strips are covered by solder mask to reduce high field exposure in LAr. Integrated inter-strip capacitors to minimize over voltage condition in a spark 0.2mm thick FR4 used for the rounded field cage corners.

8. 8 Photon Detectors (D. Warner) 35t Installation Readiness Review – Aug. 25, 2014 The 35T Photon Detector (PD) system consists of 8 individual PD Modules, arranged in the configuration shown to the right. While the photon detector technology preliminary selection has been made (sensL MicroFB 60035-SMT), the light collection technology down select still has not. 3 significant design revisions of PD module will be tested in the 35T detector: –Four modules of the nominal “4-bar” configuration testing several different wavelength shifting technologies (positions 2,3,5,7) –Three modules of the “32 Fiber PD” configuration (positions 1,4,8) –One module of the “Fiber embedded plate” configuration (position 6) Each PD module has a detector active area of approximately 500mmx100mm.

9. 9 Key Components of the Cold Electronics (H. Chen) 35t Installation Readiness Review – Aug. 25, 2014

10. 10 Front End Mother Boards 35t Installation Readiness Review – Aug. 25, 2014 FEMB is an assembly of 3 boards – Analog Mother Board! – FPGA Mezzanine! – SERDES Mezzanine!

11. 11 TPC Mechanical Stability Kinematic location of the TPC assembly –One fixed APA foot –One APA foot can slide towards the fixed foot –Long drift CPA feet are unconstrained 35t Installation Readiness Review – Aug. 25, 2014 Fixed APA foot Sliding APA foot Constrained in one dimension Unconstrained CPA feet

12. 12 TPC Mechanical Stability 35t Installation Readiness Review – Aug. 25, 2014 Distortion during cooling –The TPC structure is made up of stainless steel and G-10 –Thermal expansion/contraction considerations CTE of Stainless 7.4 x 10^6/F (-320 to 70 deg. F) CTE of structural fiberglass I-beams 3.8 x 10^-6/F (-320 to 70 deg. F) Calculated distortion from differential CTE’s and temperature change is 2.3millirads Flexible Joints are designed in the diagonal bracing: –1” pin fits with clearance. Sleeves establish clearance between members. Joint is designed for a minimum of 5 milli-radians of rotation on all axes. Exaggerated distortion due to differential CTE’s of SS Side view of TPC structure

13. 13 High Voltage Stability FEAs on known vulnerable locations of the TPC have shown that the maximum electric field exposed to the liquid argon is no greater than ~20kV/cm. The max field to the argon gas in the ullage is ~ 10kV/cm A detailed description of the FEA results can be found in docdb 9180 35t Installation Readiness Review – Aug. 25, 2014

14. 14 Testing and Data Quality APA tests: –Continuity of wires to output connectors (docdb 9399, 9439) –Integration test and noise measurement with cold electronics –Hi-pot test of wire plane insulation, CR boards –Wire tension, pitch measurement –Thermal cycle through LN 2 HV feedthrough –High voltage test of feedthrough (in LAr) and filter network Field cage –Structural fiber glass I-beam Contraction and warp in LN 2, outgassing in LAr –FR4 panels Sparking test in air, LAr TPC Structure –Distortion test during trial assembly 35t Installation Readiness Review – Aug. 25, 2014

15. 15 Documentation TPC –Mechanical drawings: UW PSL webdav –HV system: 9136, 9153 –Electric field simulation: 9180 Cold Electronics –See H.Chen’s presentation (docdb 9194) at the June 16 review Photon Detectors –See presentations from D. Whittington (9196) and D. Warner (9200) at the June 16 review 35t Installation Readiness Review – Aug. 25, 2014

16. 16 Things to do on the TPC before Installation Complete the trial assembly at PSL –Complete long drift field cage installation –Disassemble the TPC; install short drift field cage while removing the APAs Modify some parts to accommodate manufacturing tolerances Fabricate and test the faraday cages for the APAs Test the other 3 APAs with the readout electronics boards Evaluate wire repair options on the APAs Clean/label/tag TPC parts, pack and ship to FNAL 35t Installation Readiness Review – Aug. 25, 2014

17. 17 Conclusions The 35ton TPC design is complete TPC mechanical component fabrication is complete (except the faraday cages) PDs have all been installed in APAs TPC Trial assembly on going at PSL Prototype cold electronics boards tested on one 35ton APA Will deliver the TPC mechanical components to FNAL at end of Sept. for CE installation and TPC installation in the cryostat 35t Installation Readiness Review – Aug. 25, 2014

18. 18 Backup slides 35t Installation Readiness Review – Aug. 25, 2014

19. 19 APA Support 35t Installation Readiness Review – Aug. 25, 2014 APA Support –7 board APA’s are mounted to vertical beams –3 and 4 board are supported by the 7 board APA’s.

20. 20 Background of the 35ton Phase II TPC The 35t cryostat was not originally intended to have a TPC installed. It’s initial purpose was a cryogenic test to achieve liquid argon purity in a membrane cryostat. A separate test LAr1, was to be used as a test bed for the LBNE TPC’s. Due to budget tightening, LAr1 was omitted and a 35t phase II test was conceived. The 35t phase II test attempts to test LBNE like components and features (gaps, multiple APA’s, PD’s, CPA, FC, reconstruction) in as large a unit as possible, while being constrained to fit through an existing 29” manhole. The 35ton TPC is a prototyping effort. Due to budget constraints, this TPC is designed and constructed before any preliminary designs for the FD are taken place. The experiences gained here will inform future FD design tasks. 35t Installation Readiness Review – Aug. 25, 2014

21. 21 35ton TPC Requirements The 35 Ton Phase 2 Prototype shall contain the basic engineering features of the Far Detector. The 35 Ton Phase 2 Prototype shall be able to track cosmic ray particles to demonstrate that the reference design will function as planned The Far Detector L3 subsystems shall provide components or services for the 35 Ton Phase 2 Prototype The 35 Ton Prototype Cryostat shall be used, within its limitations, for the FD prototyping program. The grounding and shielding scheme for the 35T will be implemented in the design, construction and installation according to the Grounding and Shielding Guidelines developed and adopted for the final (large) detector. 35t Installation Readiness Review – Aug. 25, 2014

22. 22 Interfaces PD: Integrated into the APA. PD cable routing defined CE –FEE ASIC,FPGA,SerDes boards needs to be installed onto the APAs at FNAL. Cable routing defined, wiring inside the faraday cage defined. –Wire bias power / field cage cables defined. –Grounding scheme defined (#9132) Cryostat/Cryogenic –TPC anchoring scheme under discussion –Misc. pipes near the TPC under discussion 35t Installation Readiness Review – Aug. 25, 2014

23. 23 Resources Component Fabrication/Assembly –APAs: PSL, docdb 9182 –CPAs: Princeton, docdb 9171 –FCAs: BNL/FNAL, docdb 9176 –HV system: UCLA Trial Assembly –Techs/engineers from PSL, + L4s from each subsystems Final Assembly –Techs/engineers from PSL/FNAL, + L4s 35t Installation Readiness Review – Aug. 25, 2014