LBNF Test Cryostat Requirements David Montanari / Jack Fowler Jan 29, 2015 Rev. 11

Outline Intro Beam Cryostat requirements Cryostat top requirements Cryogenic system requirements Summary 2

Intro The goal of this prototype is to study, characterize and validate the design of the full scale detector components for a future far detector of a neutrino long baseline, which aims to study neutrino oscillations, search for CP violation in the lepton sector and perform other physics measurements. To test beam data for at least one additional beam direction at a relative large angle with respect to the drift direction would be a valuable cross-check of reconstructing modeling. This could be a second phase for the prototype. The general idea is to build a flexible facility that can host other detectors in the future. In order to achieve 100% containment, the active detector volume would have to be at least 5 m in longitudinal direction and ~4-5 m in the transverse direction (with respect to the beam). 3

Beam The H4ext beam line in EHN1 at CERN can provide electron, muon, pion and proton beams. The charged particle momentum is selectable and covers range from 200 MeV to ~10 GeV. The nominal configuration is to steer the beam horizontally into the cryostat with the option of bending the beam up to +/- 10 degrees to study angular dependence. 4

Assumptions for TPC configuration APA: three (3) wide and one (1) high. 6,000 mm x 2,300 mm APA dimensions. Equates to ~ 6,884 mm total height. Also assumes the frame will be produced with 4” x 3” structural tubing. – Note: the cryostat height will be based on a 6,600 mm APAs even though we plan to use 6,000 mm APAs to allow flexibility for future testing. CPA: to cover APA area CPA-APA-CPA, with the possibility to do APA-CPA-APA. Drift distance: 2,500 mm for each side of APA. Orientation: parallel to the walls of the cryostat. Clearances: – 300 mm from floor to CPA to prevent HV discharge. – 1,000 mm on 3 sides to allow for access and egress around the outside of the TPC. – 300 mm of liquid above the CPA to prevent HV discharge. – 1,200 mm on hatch end of TPC for cryogenic piping and instrumentation. Ullage: 900 mm (based on the far detector design). 5CERN test Cryo size discussion 16-Jan-2015

ParameterValue Type of structureMembrane cryostat Membrane material SS 304/304L, 316/316L or equivalent. Other materials upon approval. FluidLiquid Argon (LAr) Outside reinforcement (Support structure) Self standing concrete/steel enclosure with frost prevention (Floor + Sides) TPC size Length: 3 x 2.30 = 6.90 m Width: 2 x 2.50 = 5.00 m Total Height: 6.9 m Minimum inner dimensions (flat plate to flat plate) Physics requirements + Installation. Assumes 0.9 m ullage (LBNF value) 7.3 m (W) x 9.5 m (L) x 8.4 m (H) Maximum static heat leak10 W/m^2 Operating gas pressurePositive pressure. Nominally 1.0 psig (~70 mbar). Design Pressure (Discussion in progress)5.0 psig (~350 mbar) + LAr head Design Temperature77 K (liquid Nitrogen temperature for flexibility) All surfaces in the ullage during operations< 100K Max noise/vibration/microphonics inside cryostatLAr pump outside the cryostat Beam window (Work in progress)In the center of the active volume Accessibility after operationsCapability to empty the cryostat in 30 days and access it in 60 days Lifetime / Thermal cycles Consistent with the LAr program TBD Cryostat Requirements – 1 6

ParameterValue LAr Loading on the floor of the cryostat15 psi Total force on the floor of the cryostat (LAr mbarg GAr) 782 ton (at the point of action) Total force on the sides of the cryostat (LAr mbarg GAr) 346 ton (short side), 450 (long side) at the point of action Max noise/vibration/microphonics inside cryostatLAr pump outside the cryostat Beam window (Work in progress)At the center of the active volume Accessibility after operationsCapability to empty the cryostat in 30 days and access it in 60 days Lifetime / Thermal cycles Consistent with the LAr program TBD Cryostat Requirements – 2 7

EHN1 CERN test Cryo size discussion 16-Jan CERN cryostat Pit B Bridge Crane LBNE cryostat

Plan view – EHN1 CERN test Cryo size discussion 16-Jan CERN cryostat Pit B LBNE cryostat Bridge Crane

Side view TPC in Cryostat CERN test Cryo size discussion 16-Jan Top cap Containment vessel Liquid level APAs Insulation Membrane

End view TPC in Cryostat CERN test Cryo size discussion 16-Jan ,142 mm

Crane clearance above TPC/Cryo CERN test Cryo size discussion 16-Jan Hook height 9.9 m above gallery floor Current hook height above cryostat as modeled 7,709 mm top cap thickness included Pit B depth 9.0 m

Cryostat Top

ParameterValue ConfigurationRemovable metal plate reinforced with trusses anchored to the membrane cryostat support structure. Contains multiple penetrations of various sizes and a manhole. Number, location and size of the penetrations TBD. Provisions shall be made to allow for removal and re-welding six (6) times. Plate/Trusses non-wet materialSteel if room temperature. SS 304/304L or equivalent if at cryogenic temperature. Wet materialSS 304/304L, 316/316L or equivalent. Other materials upon approval. FluidLiquid Argon (LAr) Design Pressure (Discussion on-going)5.0 psig (~350 mbar) Design Temperature77 K (liquid Nitrogen temperature for flexibility) Inner dimensionsTo match the cryostat Maximum allowable roof deflection0.024 m Maximum static heat leak15 W/m^2 (Greater than sides/bottom to allow for the penetrations) All surfaces in the ullage during operations< 100K Additional design loads-Top self-weight -TPC (~3,000 kg on each anchor) -TPC anchors (TBD) -Live load (488 kg/m^2) -Electronics racks (400 kg in the vicinity of the feedthroughs) -Services (150 kg on every feed through) TPC anchorsCapacity: 3,000 kg each anchor. Number and location TBD (Minimum 6). Cryostat Top Requirements – 1 14

ParameterValue Hatch opening for TPC installation3,550 mm x 2,000 mm Grounding plate1.6 mm thick copper sheet brazed to the bottom of the top plate. Lifting fixturesAppropriate for positioning the top and the different parts that constitute it. Cold penetrationsMinimum 4. Location and design TBD. Lifetime / Thermal cycles Consistent with the LAr program TBD. Cryostat Top Requirements – 2 15

Infrastructures

Assumptions for external cryostat dimensions Outer support structure thickness: 500 mm. Insulation thickness: 800 mm (might be 900 mm??). Top cap thickness: 1,500 mm. Cryostat external dimensions: 11,191 mm (H) x 12,122 mm (L) x 9,882 mm (W). Hook height above floor of pit B: 18,900 mm. Hook clearance over top cap: 7,709 mm. APA height: 6,289 mm. Clearance between height of APA and hook over cryostat: 1,420 mm. 17CERN test Cryo size discussion 16-Jan-2015

ParameterValue Cryostat footprint (estimate)12,122 mm (L) x 9,882 mm (W) Work area around the top of the cryostat (platform type)2.0 m around the whole perimeter Lay down spaceWill be defined in MOU Crane coverageOver the cryostat and the lay down space Crane capacity for TPC (Not including top cryostat)5 ton Minimum hook height above the cryostat for TPC installation4.5 m Clean Room space??? Do we need it ??? Cryostat Infrastructures Requirements 18

ParameterValue Isolation1)The cryostat membrane and any supporting structure, whether it is a steel structure or a concrete and rebar pour, shall be isolated from any building metal or building rebar with a DC impedance greater than 300 kohm. 2)All conductive piping penetrations through the cryostat shall have dielectric breaks prior to entering the cryostat and the top plate. Grounding1)The cryostat, or “detector” ground, shall be separated from the “building” ground. 2)A safety ground network consisting of saturated inductors shall be used between detector ground and building ground. 3)Parameters TBD. Top plate grounding 1)If the cryostat is contained within a concrete pour, the top plate shall be electrically connected to any rebar used in that pour, and the rebar shall be conductively tied at regular intervals. Parameters TBD. 2)The top grounding plate shall be electrically connected to the cryostat membrane by means of copper braid connections. a)Each connection shall be at least 1.6 mm thick and 63.5 mm wide. b)The length of each connection is required to be as short as possible. c)The distance between one connection and the next one shall be no more than 1.25 m. d)The layout can follow the profile of several pieces of insulation, but it shall be continuous. e)The DC impedance of the membrane to the top plate shall be less than 1 ohm. Cryostat Grounding/Isolation Requirements 19 Note: The layout of the top plate grounding is outlined in the next slide.

Top plate grounding layout 20

Cryogenic System

ParameterValue LocationPreferably not in front of the cryostat (on the beam) LAr purity in cryostat10 ms electron lifetime (30 ppt O2 equivalent) GAr Piston purge rate of rise 1.2 m/hr Membrane cool-down rate From manufacturer TPCs cool-down rate < 40 K/hr < 10K/m (vertically) Mechanical load on TPC The LAr or the gas jet pressure shall not apply a mechanical load to the TPC greater than 200 Pascal. Nominal LAr purification flow rate (filling/ops) 5.5 day/volume change All surfaces in the ullage during operations< 100K GAr purge within insulation 1 volume change/day of the open space between insulation panels Lifetime of the cryogenic system Consistent with the LAr program TBD Cryogenic System Requirements 22

Summary 8.4 m (H) x 9.5 m (L) x 7.3 m (W) is the internal size required by the TPC elements. Using the assumptions listed (800 mm insulation, 500 mm outer structure, 1,500 mm top cap), the external dimensions are: 11.2 m (H) x 12.1 m (L) x 9.9 m (W). The goal is to be able to run the detector before the long shut-down. The design should start as soon as practical with GTT. The specifications should be formalized in a format that can be used to issue a contract. 23CERN test Cryo size discussion 16-Jan-2015

Backup

Cryostat sizing Length APA width 2300 mm (x 3) mm of edge boards on each side of the center joint (x 4). 50 mm from the SS APA (active area boundary) frame to field cage (x 2) mm diameter of CPA tube (x 2) mm clearance to membrane for access and egress mm clearance for piping and instrumentation. 60 mm depth of corrugations (x 2) mm total length of cryostat. 25CERN test Cryo size discussion 16-Jan cm

Cryostat sizing Width 76.2 mm - APA thickness 3” mm height of wire layers on each side (x 2) mm drift distance (x 2) mm – Half the diameter of 3” CPA frame (x 2) mm to membrane for access and egress (x 2). 60 mm depth of corrugations (x 2) mm total width of cryostat. 26CERN test Cryo size discussion 16-Jan-2015

Cryostat sizing Height for 6.6 m APA 6,638.7 mm - APA side tube length mm - Distance from top of the cross tube down to the beginning of active volume mm – Diameter of CPA tubing above active volume. 300 mm of liquid above CPA tube. 16 mm boards at bottom of frame mm – Diameter of CPA tubing below APA bottom boards. 300 mm of liquid below CPA tube. 100 mm of space reserved for piping at bottom of cryostat. 7,491 mm is liquid level height. 900 mm ullage based on far detector design. 60 mm depth of corrugations (x 2) Total height from floor to underside of top cap = 8,391 mm. Total inner volume 582 m 3. 27CERN test Cryo size discussion 16-Jan-2015 Floor of Cryostat Space for piping CPA APA APA active volume Liquid Volume Bottom boards of APA

Cryostat Height sizing (6.0 m APA) 6,060.1 mm - APA side tube length 76.2 mm - Distance from top of the cross tube down to the beginning of active volume mm – Diameter of CPA tubing above active volume. 300 mm of liquid above CPA tube. 16 mm boards at bottom of frame mm – Diameter of CPA tubing below APA bottom boards. 300 mm of liquid below CPA tube. 100 mm of space reserved for piping at bottom of cryostat. 6,912 mm is liquid level height. 900 mm ullage based on far detector design. 60 mm depth of corrugations (x 2) Total height from floor to underside of top cap = 7,812 mm. Total inner volume 542 m 3. 28CERN test Cryo size discussion 16-Jan-2015 Floor of Cryostat Space for piping CPA APA APA active volume Liquid Volume Bottom boards of APA

Conclusions 8.4 m H x 9.5 m L x 7.3 m W is the internal size required by the TPC elements. Using the assumptions listed, this yields these external dimensions – 11.2 m H x 12.1 m L x 9.9 m W. How this fits into the overall plan and layout for pit B needs to be evaluated. There are some opportunities to reduce the size if necessary. – Design cryostat height for 6.0 m APAs. – Reduce the access and egress around the TPC. – Reduce the ullage. – Move cryogenic equipment outside of cryostat. – Reduce number of APAs. 29CERN test Cryo size discussion 16-Jan-2015

Current cryostat schedule Preliminary Design: Fen-Jun Design Review: Jul-Sep Final Design/Procurement: Oct 2015-Sep Construction: Oct 2016-Jul CERN test Cryo size discussion 16-Jan-2015