Dual Phase Field Cage Status DUNE HV Consortium

Dual Phase Field Cage Status DUNE HV Consortium Meeting December 20, 2017 Jaehoon Yu for A. Chatterjee, G. Brown & UTA Team A. Gendotti, S. Murphy, C. Cantini & ETH Team F. Pietropaolo & CERN Team

Contents • DP FC Design Concept • HV Divider board design and component testing status • DP FC Trial Installation Status • Summary 2 12/20/17 Jaehoon Yu | DP FC Status

Field Cage in proto. DUNE DP § Field Cage and cathode hangs off of the ceiling § Essential to have light yet sturdy structure § Based on modular concept as SP Charge Readout Planes Field Cage (common structural elements with SP) 6 m 6 m 3 12/20/17 Jaehoon Yu | DP FC Status Catho de

Field Cage Design • Shares common basic structural elements w/ Proto. DUNE-SP • Consists of 8 vertical modules of 6310 x 3010 mm 2 (2 modules per detector face) • Each module is assembled out of 3 distinct sub-modules • Three distinct types of sub-modules with 33, and 32 profiles each held by a frame with two 6” and two 3” horizontal FRP I-beams • 98 electrically continuous rings in 60 mm pitch using straight aluminum clips • Each profile is made of extruded aluminum with a supporting rib running in the middle • 11 profiles with one end bent at 45 degrees are electrically connected by 2 divider boards Sub-module 1 33 profiles • Inter-module connections made with FRP plates connected with FRP threaded rods Sub-module 2 33 profiles Sub-module 3 32 profiles + cathode Continuity at center and borders w/ Al clips 4 12/20/17 Jaehoon Yu | DP FC Status

HV Divider Board Mounting to DC A. Gendotti 5 12/20/17 Jaehoon Yu | DP FC Status • Two parallel columns of 10 boards, totaling 20 boards • The total potential from the extraction grid to cathode: 294 k. V to 588 k. V • Two 2 GW resisters each stage for each board, providing 0. 5 GW effective resistance per stage • Current through the entire circuit: 6 m. A – 12

FC Production Status § The production for 24+3 sub-modules completed and shipped to CERN § Additional spares have been ordered and will be conditioned and preassembled at UTA for shipping if necessary at CERN § HVDB boards (18+1 long and 2+1 short) have been certified and at CERN § A protective epoxy coating on the solder balls in between the profiles have been done at CERN § All boards have been recertified and ready for mounting § Per CERN group suggestion, an additional protective boards have been designed and being 6 12/20/17 Jaehoon Yu | DP FC Status

Activity at CERN § Two UTA students stayed at CERN from 11/19 – 12/8 for a trial installation which planned to have 3/8 of FC installed § Have been trained for the elevating platform operation for FC installation work § They assembled 8 out of the 9 sub-modules when JY joined them on 11/30 for his three week stay § One sub-module was left to train the CERN technicians § Floor trial assembly of the three top sub-modules along with three HVDB mounted on Dec. 8 7 § Al clips connected the profiles in the straight and 90 degree section § Resistance measurements performed at the far end of the 12/20/17 Jaehoon Yu | DP FC Status board and showed good results (consistently ~980 MOhm

Floor Trial Assembly of Top Row 8 12/20/17 Jaehoon Yu | DP FC Status

DP FC Installation at CERN § Load testing with 180 kg each for each of the 6 winches and cables completed the morning of Monday, Dec. 18 § Gendotti and Yu together with two CERN technicians and Resnati installed two sub-modules in 2. 5 hours § Installation sequence for a panel: 9 1. SS I-beams with SS L-brackets are mounted onto the cables and raised to ~2 m by the two manual winches top of the cryostat 2. Top sub-module placed under the SS I-beam and lower the I-beam into the FRP I-beams of the module and connect the module to SS I-beam 3. Raise the connected top sub-module to ~2 m | DP FC Status 4. 12/20/17 Place. Jaehoon the Yumiddle sub-module and connect it to the top

Module Connection Details 10 12/20/17 Jaehoon Yu | DP FC Status

DP FC Installation at CERN § Gendotti, Yu together and two CERN technicians continued the installation of the 2 nd two sub-modules yesterday § Needed help from Dominique Ducheneau to raise the manual winch § Took ~40 min to install the SS I-beam and the top submodule § Took another ~45 min for the second module due to the potential interference with the existing module § Due to cryo-pipe installation ongoing through the end of the week, the floor had to be removed, preventing us to continue installation § Raised the two modules above 2 m height and connected the two modules with the horizontal bar 11 Jaehoon Yu | DP FC Status to 12/20/17 prevent unexpected motion damaging the

First Two Modules 12 12/20/17 Jaehoon Yu | DP FC Status

● Summary All FRP and other parts for DP FC have been conditioned and delivered to CERN ● ● HVDB boards with the minimal spares certified and delivered at CERN ● ● 13 Remaining spares will be produced, tested in warm and cold, certified and shipped to CERN early 2018 Trail installation of 2 partial panels of the 8 total completed in the past two days Installation was seamless and quick (~ 1 hour per submodule) but requires minimum four people ● ● All packages are in the CRB Two on the winches and two for module connection and safety We’ve learned tremendously from the trial installation We have obtained a reasonable confidence that the installation of FC will be expeditious, barring any 12/20/17 Jaehoon Yu with | DP FC Status interferences other parts 13