lar1-nd cryogenics concept david montanari neutrino cryogenics requirements meeting 24 september...
TRANSCRIPT
LAr1-ND Cryogenics Concept
David Montanari
Neutrino Cryogenics Requirements Meeting
24 September 2014
Outline
• Introduction• Building layout• Requirements• Current concept• Outstanding issues• Design choices• Summary
Sep 24, 2014David Montanari | LAr1-ND Cryogenics Concept2
Introduction
• The Short-Baseline Neutrino Program (SBN) at Fermilab will study neutrino properties using a combination of detectors:
– existing MicroBooNE– new LAr1-ND (Near Detector)– a refurbished ICARUS T600 (Far Detector)
• These slides describe the current thoughts on the cryogenic system for the LAr1-ND detector.
• The base design is a membrane cryostat of 129 m3 (LAr volume) or 180 ton LAr Mass.
• The cryostat will be housed in a new dedicated building next to the SciBooNE enclosure, where the cryogenic system will be located. The two buildings will be connected with a tunnel through which interconnecting lines will connect the cryostat to the cryogenic system.
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Note: it may be possible to increase the sensitivity by increasing the LAr volume. We have looked into extending the width to 5.75 m (from 4.4 m) , that is 168 m3 LAr volume. This will allow the insertion of two (2) 2.5 m wide APAs instead of one (1) 3.65 m wide.
Layout for LAr1-ND similar to the LBNE 35 ton prototype
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LAr/GAr transfer lines
Process piping
North
LAPDLBNE 35 ton Cryostat
LAPD/LBNE LAr purification/filtration systemLAr/GAr transfer lines
Process piping
1.3-2.6 vol change/day
David Montanari | LAr1-ND Cryogenics Concept Sep 24, 2014
• This is the 3D model of PC-4 with the LBNE 35 ton and LAPD.• We plan to do the same with LAr1-ND and the cryogenic system.
Near Detector Building – Plan view at detector level
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Wetland Delineation – June 2014
From S. Dixon, Sep 16 ,2014
Cryogenic System for detector
Cryostat
Near Detector Building – Section view
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From S. Dixon, Sep 16 ,2014
Cryogenic System for detector
Cryostat
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Parameter Value
LAr purity in cryostat 3 ms electron lifetime (100 ppt O2 equivalent)
GAr Piston purge rate of rise 1.2 m/hr
Membrane cool-down rate From manufacturer (most likely < 10-15 K/hr)
TPCs cool-down rate< 40 K/hr < 10 K/m (vertically)
Mechanical load on TPCThe 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) 1 volume change/day
All surfaces in the ullage during operations < 100 K
Convective currents inside cryostat < 10 cm/s
GAr purge within insulation1 volume change/day of the open space between insulation panels
Lifetime of the cryogenic system 10 years (5 years of run + 5 years potential upgrade)
• Portable system(s) lowered through the top in the SciBooNE hall, with quick connections to/from the cryostat.
• Scalable system(s) to be used for future larger detectors.
• Cryogenic and GAr/LAr purification systems to LBN design (where possible).
Sep 24, 2014David Montanari | LAr1-ND Cryogenics Concept
Cryogenic system requirements
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Parameter (SciBooNE) Value
Available footprint 4.9 m x 5.1 m (To be verified)
Available height 11.5 m (two catwalks at intermediate levels)
Accessibility Access from the top through the roof
Lifting equipment Jib crane
Connection to cryostat building Underground tunnel
Sep 24, 2014David Montanari | LAr1-ND Cryogenics Concept
Space constraints
• See picture and drawing in next slide.
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SciBooNE
8,53
4 m
m3,
048
mm
4,900 mm
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Parameter Value
LAr purification flow rate (filling/ops) 1 volume change/day: 5.4 m3/hr = 24 gpm (129 m3)
Cooling power Cool-down: 14 kW (129 m3)Operations: 2.2 kw (129 m3) + TBD
• Portable system(s) lowered through the top in the SciBooNE hall, with quick connections to/from the cryostat.
• Scalable system(s) to be used for future larger detectors.
• Cryogenic and GAr/LAr purification systems to LBN design (where possible).
• LN2 refrigeration based on LBN design is not cost effective.
Sep 24, 2014David Montanari | LAr1-ND Cryogenics Concept
Cryogenic system current design parameters
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LAr1-ND PFD of LAr systems (based on 35 ton)
Sep 24, 2014David Montanari | LAr1-ND Cryogenics Concept
• This is the PFD of the LAr system of LAr1-ND based on the 35 ton concept (but with an external LAr pump and a system to spray clean LAr/GAr on the top to keep the ullage cold, ≤ 100 K).
• Assumption: 129 m3 tank (base option).
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• This is the PFD of the LN2 system of LAr1-ND based on the 35 ton concept and CERN initial idea as presented by Johan Bremer on Jun 18, 2014.
• Assumption: 129 m3 tank (base option).
LAr1-ND PFD of LN2 system (based on 35 ton and Johan B)
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129 m3 231 m3
Sep 24, 2014David Montanari | LAr1-ND Cryogenics Concept
Cryogenic LAr filter for LAr1-ND Conceptual (from Mark A.)
Old option
Purification/Filtration system needs
• Gas purge/recirculation: GAr purification during initial cleaning.• Filling: LAr purification.• Operations: LAr + GAr boil off purification.• GAr purge inside the insulation.
• LN2 tanker delivery to onsite LN2 dewar (10,000 gal available from D0):– Five (5) year usage based on estimated heat leak.
• LN2 Refrigerator based on LBN cycle NOT cost effective:– Estimated Cost of LN2 plant (Design, Procure, Install).– Power + GN2 costs.
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Cryogenic system capabilities – 1
• To purify the LAr (filling and operations).• To re-condense and purify the boil off gas.
– LAr condenser and LN2 phase separator.– LAr circulation pump to send LAr to purification system
• To handle the LAr/GAr and LN2/GN2 flows:• Initial cleaning GAr purging and venting, GAr recirculation and purification.• Ops cool down, LAr filling, GAr boil off purification and re-condensation, LAr purification, LAr
return to the tank.• Make-up GAr.
• To maintain the top of the cryostat at ≤ 100 K.• To monitor and control internal and external pressure:
• Pressure Control / Vacuum Protection• PSV, VSV, Auto/Manual venting.
• To handle the GAr purge inside the insulation.• Instrumentation and diagnostics: T and P sensors, flow meters, liquid level
sensors, etc., analytical instruments to measure the contamination, in-line Purity Monitors (??), etc.
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Cryogenic system capabilities – 2
• To sample GAr from the ullage and measure the concentration of contaminants.
• Control system.• Flexibility: new features may be tested (cold roof, LAr external pump). To the
extent possible, it is desired to have a flexible system where we can turn on/off the various features for comparison.
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Current list of penetrations through the top of the cryostat
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• Liquid level probe(s).• LAr Out (to LAr pump through the side of the tank)• LAr In (from pump discharge through purification system)• Cool-down ports (depending on cool down method)• GAr purge inlet• GAr purge outlet• GAr to condenser and vent valves• Low P make-up GAr• PSV• VSV• LAr cool-down• T sensors• T sensors Feedthrough• Miscellaneous Feedthrough (LED lights, etc.)• TPC Signal Feedthroughs (warm or cold ??)• TPC HV feedthroughs (on center of cryostat)• Photon detectors• Calibration(s)• Purity Monitor(s)?• Glass window view port ??• Sampling ports• LN2/GN2 heat exchanger ports• Instrumentation & Diagnostics ??• Spare ports
Outstanding issues
• Portability/Scalability: studies on portability and how to design a portable/scalable system that can serve present and future generation detectors of any size.
• Studies on LN2 system design to be common (to the extent possible) to T600 (FD). Will be different than that of larger systems because of cost of LN2 refrigeration.
• Studies on how to keep all surfaces at a Temperature lower than 100 K.• Studies on how to minimize noise in the vicinity of the wires (may also be coming
from piping layout).• LAr Pump (Outside):
– Need to see how to isolate the pump electrically and mechanically from the TPC. Issues with electronic noise and microphonics.
– Check grounding scheme.
• Ability to make modifications after run for 5 years– Access the tank.
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Design choices
• Which LAr filtration system ??– Molecular sieve + Copper beds.– ICARUS style.
• Which LAr condenser ??– Ar in tube and LN2 in shell– Ar in shell and LN2 in tube
• Which interface with cryostat ??– Bayonet fittings.– Flanged connections.– Where is the boundary.
• Process controls strategy.
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Summary
• Preliminary thinking has been done on the layout of LAr1-ND cryogenic system for the base design (129 m3 cryostat).
• A larger cryostat (231 m3) was analyzed and discarded for cost considerations. The 168 m3 version is a recent proposal and has not been analyzed yet from the cryogenic system standpoint. The purification flow rate and cooling power will slightly increase.
• Cryogenically the system ‘feels like’ the 35 ton system at Fermilab’s PC-4 but placed in separate facility.
• The requirements for the cryogenic system have been developed and are being finalized.
• LAr cryogenic system is thought to be a scaled-up version of that of 35 ton/LAPD.
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Closing remark
• Fundamentally there are no foreseen issues related to increasing the cryostat size. There are increased costs for the cryogenic system (as well as the cryostat). They will scale with heat leak and the purification flow rate (and the cryostat surface).
• The design issues which is key:1) How do we keep the surfaces of the ullage at T ≤ 100 K ?
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Thanks!
David Montanari
Neutrino Cryogenics Requirements Meeting
24 September 2014
Backup
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Current schedule
• The goal is to have the detector ready for commissioning in the fall of 2017 and to take beam data in Apr 2018.
• From the proposal submitted to the PAC in Jul 2014:
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Milestone Date
Cryogenic plant proposal submitted for peer review Mar 2015
LAr1-ND technical proposal submitted for peer review Mar 2015
Cryogenics procurement plans released and active Sep 2015
Start cryogenic plant commissioning Aug 2017
Start detectors cooling and commissioning Nov 2017
Start data taking with beam Apr 2018
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LN2 refrigeration conceptual (From Mark A.)