Post on 16-Dec-2015
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The Long-Baseline Neutrino Experiment Project
LBNE 35 ton prototype
Phase 1 summary
Terry Tope
Fermi National Accelerator Laboratory
tope@fnal.gov
All Experimenters’ Meeting – Fermilab – May 19, 2014
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• LBNE wants to build a 10 kton Fiducial Mass Liquid Argon detector (two 5/9.3 kton FM/TM for a total of 19.8 kton ).
• Membrane cryostat technology with passive insulation (Polyurethane foam).
• We have built the LBNE 35 ton prototype (the first and only membrane cryostat for scientific purpose and available to scientists) with the Phase 1 goals of:– demonstrating the contractual business model with membrane cryostat
supplier for the design and construction of a membrane cryostat DONE.– demonstrating the membrane cryostat technology (thermal performance,
feasibility for LAr, leak tightness) DONE.– demonstrating that we can achieve the purity requirements in a membrane
cryostat W/O evacuation DONE.• equivalent O2 contamination 229 ppt, -> 1.4ms e- lifetime• from 9 to 1 Signal/Noise Requirement for minimum ionizing particle at a 3.48m
drift distance and 500V/cm drift field.
– achieving and maintaining purity requirements during filling, purification and maintenance mode DONE.
Background and Phase 1 Goals
LBNE 35 ton prototype – All Experimenters’ Meeting – May 19, 2014 – Fermilab
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Tank Interior
LBNE 35 ton prototype – All Experimenters’ Meeting – May 19, 2014 – Fermilab
Liquid argon pumps
Purity monitors(drift chambers)
2.7 meters
4 metersCool-down liquid sprayers
Argon purge distribution
4LBNE 35 ton prototype – All Experimenters’ Meeting – May 19, 2014 – Fermilab
Gas vented toatmosphere
H20, limited by outgassing
N2 not removed by Filters~32h
rs
~7days
PistonPurge
Recirculation
Room Temperature Argon Gas Purification
“Dry
Air
”
Plot by Alan Hahn
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Liquid Argon Cryogenic Purification
LBNE 35 ton prototype – All Experimenters’ Meeting – May 19, 2014 – Fermilab
Life
time
(s)
12/1
8--In
itial
Fill
(70%
)12
/20—
Pum
p “A
” St
arts
12/3
0—Sw
itch
to P
ump
“B”
1/6—
Top
off L
Ar (
100%
)
1/31
—Sw
itch
Back
to P
ump
“A”
Vario
us S
tudi
es
2/7—
Turn
off
Pum
ping
2/13
—Be
gin
Pum
p ou
t of L
Ar
sent
to M
icro
BooN
E
Bottom Long PrM2Top Short PrM4
First e- lifetime measured, 460us, 41 hr after start of pumping
2 filtration volume changes per day
LBNE e- lifetime requirement
Plot by Alan Hahn
100 ppt O2 equiv
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• Build a complete functional reduced-scale sized TPC with Photon Detectors inside the 35-ton cryostat.
• TPC components will closely resemble the full size counterparts.
• Anode Plane Assemblies (APA) will incorporate functional photon detectors
• Goals of this prototype TPC– Validate the design of nearly all Detector components (at a small scale); testing
the integrity of all components and their interconnects in LAr.– Study the performance of the wire wrapping readout scheme, and the impact of
the gaps between APA modules.– Study the electronics noise contribution from potential sources: acoustic, pump,
flow driven wire or field cage motion, high voltage ripple coupling, coupling between digital and analog circuits, etc.
Phase 2 Goals – Operation Winter 2014
LBNE 35 ton prototype – All Experimenters’ Meeting – May 19, 2014 – Fermilab
7LBNE 35 ton prototype – All Experimenters’ Meeting – May 19, 2014 – Fermilab
LBNE Style TPC in 35T Cryostat
~2m drift region
20 cm short drift region
Photon Detectors (8 total) in 4 APAs
J. Fowler
Cosmic Ray Counters (CRCs)
Field Cage not shown
Cathode PlaneCathode Plane
CRCs
CRCs