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