Photon Detector Designs for the Deep Underground Neutrino Experiment

Photon Detector Designs for the Deep Underground Neutrino Experiment 28 August, 2015 Denver Whittington Indiana University Outline ➢ Light guides ...
Author: Rhoda Phillips
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Photon Detector Designs for the Deep Underground Neutrino Experiment 28 August, 2015

Denver Whittington Indiana University

Outline ➢

Light guides for a single-phase TPC ➢ ➢

Baseline design Alternatives



Silicon photomultipliers



Design testing in LAr at FNAL ➢ ➢

Data-simulation comparisons Preliminary results from recent test



Scintillation structure analysis



Xenon-doped LAr

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Light Guides for Large-Area Photon Detection ➢

Large active-area UV-collecting light guides ➢

Acrylic or polystyrene imbued with wavelength-shifting compound ➢ ➢



Based on design pioneered by MIT Dip-coating w/ TPB in solvent (after studying many different methods)

430 nm light propagated by total internal reflection to end

Si PM

Ar ra y

128 nm LAr scintillation light



430 nm shifted light (in bar)

Embed PD paddles inside anode plane assembly behind collection wires ➢

➢ ➢

Large photosensitive area with small photocathode area Low-voltage SiPM bias Easily scalable

D. Whittington - DUNE Photon Detection - LIDINE 2015

t0

28 August 2015

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Light Guides for Large-Area Photon Detection ➢

Multiple light guide designs under investigation ➢



Alternative designs decouple UV wavelength shifter (WLS) from transport for improved attenuation Dip-coated acrylic bars ➢ ➢ ➢ ➢



WLS panel (VUV → blue) + imbedded WLS fibers ➢ ➢



Louisiana State U, center Two SiPMs (one at each end)

WLS radiator (VUV → blue) + WLS fibers (blue → green) ➢ ➢



Baseline design Indiana U, right-most paddle Nine SiPMs (3 per bar) One MIT bar (new recipe, 2nd fill)

Colorado State U, left-most Six SiPMs at top

WLS Radiator (VUV → Blue) + WLS bar (blue → green) Indiana U, cartoon below Si PM

Ar ra y



D. Whittington - DUNE Photon Detection - LIDINE 2015

128 nm LAr scintillation light

430 nm shifted light from plate ~490 nm shifted light (in bar)

28 August 2015

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Silicon Photomultipliers ➢

Reverse-biased array of photodiodes ➢ ➢

Low noise (few Hz in cryo) Excellent charge resolution

SensL MicroFC-60035-SMT 6 × 6 mm package >19,000 microcells

Dark noise characteristics in LN2 at Vbias = 24.5 V



SiPM Signal Processor (SSP) ➢

150 MHz waveform digitizer ➢



Argonne Natl. Lab HEP Elec. Group

Resolve fine waveform details ➢ ➢

~3 ns timing resolution 13 μs waveform buffer

D. Whittington - DUNE Photon Detection - LIDINE 2015

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Design Tests in LAr at Fermilab ➢

“TallBo” facility at FNAL ➢



Ultra-high purity liquid argon ➢ ➢



Vacuum to remove residual atmosphere Condenser to maintain closed system

Multiple lightguide designs ➢ ➢ ➢ ➢



84” LAr dewar

Dip-coated acrylic bars WLS fibers w/ TPB-coated acrylic radiator WLS fibers in TPB-coated acrylic panel WLS bar w/ TPB-coated radiator plates (Summer 2015)

Hodoscope (cosmic ray) trigger ➢

2 8x8 Arrays of PMTs + BaF2 crystals ➢



CREST cosmic-ray balloon exp't.

2 scintillator paddle planes ➢

Allows shower rejection, reconstruction of single tracks

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Technologies and Phase 1 vs Phase 2 ➢

Run divided into two LAr fills (“phase 1” and “phase 2”)



Only tracks passing “in front” of the paddles selected ➢ ➢



Simplify comparisons (several one-sided light guides in phase 2) Reject any tracks passing through a light guide

Data taken with hodoscopes positioned at two heights ➢

“high”

and

D. Whittington - DUNE Photon Detection - LIDINE 2015

“low”

track selections

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Preliminary Performance Results from Phase 1 Designs ➢

Ensemble of signals from “high” selection versus “low” selection WLS Fibers + TPB Radiator



Minimal attenuation loss

WLS fibers in TPB-coated panel ➢



TPB Dip-Coated Acrylic

WLS fibers + TPB radiator ➢



WLS Fibers in TPB-Coated Panel

Minimal attenuation loss (sum of signal at both ends)

TPB dip-coated acrylic bars ➢ ➢

Brightest at readout end Most substantial attenuation loss

D. Whittington - DUNE Photon Detection - LIDINE 2015

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Baseline Design Comparisons (Phase 1 vs Phase 2) ➢



Ensemble of signals from “high” selection versus “low” selection TPB Dip-Coated Acrylic (3 Bars)

TPB Dip-Coated Acrylic (1 Bar)

TPB Dip-Coated Acrylic (1 Bar)

3 bars – 9 SiPMs

1 bar – 3 SiPMs

1 bar – 3 SiPMs

Extrapolate mean response from phase 1 to phase 2 ➢ ➢ ➢



Comparable track selections and contamination levels Expect ~25 PE mean response (in right two plots) Measure substantially less

Likely seeing variability in manufacturing results ➢ ➢

Known issue, experienced many times with this technique Identical procedures → wide range of performance

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Preliminary Performance Results from Phase 2 Designs ➢

Three example double-sided designs (same track selections) WLS PVT + TPB Acrylic Plates



WLS PS + TPB Acrylic Plates

Alternate design (WLS bar + TPB plates) improves on baseline design ➢ ➢ ➢



Dip-Coated Acrylic (New MIT Recipe)

Factor of 2 better than baseline (phase 1) Factor of 8-10 better than baseline (phase 2) Substantially improved attenuation

New dip-coating recipe from MIT improves even further ➢ ➢

Almost a factor of 2 more sensitive than alternate Substantially improved attenuation

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Efficiency from Data-Simulation Comparison (In Progress) ➢

Signals from example hodoscope trajectory (Fall 2014)



Data: integrated charge in 10 us waveform [PE]



Sim: number of incident photons from the line source (toy MC)

SiPM



Estimated detector efficiency ➢

Ratio = [ Mean #γ Detected (data) ] / [ Mean #γ Incident (sim) ]

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Scintillation Structure Analysis ➢

Time structure of signal at SiPM ➢

Deconvolve average waveform from cosmic rays using measured single-PE response (dark noise) SiPM Response to Cosmic Ray Signals SiPM Response to Dark Noise





Deviation from simple double-exponential in intermediate (~100 ns) and late (> 7 μs) times

Deconvolved Signal at SiPM

Important to understand for timing resolution and pulseshape discrimination

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Scintillation Structure Analysis ➢

Three- or four-component models capture all features ➢







➢ ➢



Consistent result for prompt singlet signal (~25%) and 1.5 μs “late light” Evidence for long (~7 μs) component in acrylic light guides (not present in polystyrene)

Alternative model treats intermediate and long components as instrumental ➢

Deconvolved Signal at SiPM w/ 4-Component Fit

Deconvolved Signal at SiPM w/ Alternate Model

e.g. non-exponential tail in emission from WLS+plastic Results still consistent among light guides Lifetimes unchanged Singlet signal 34-39% of total

Publication in preparation

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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Scintillation Signal from Xenon-Doped Liquid Argon ➢

Injected xenon into the liquid argon ➢ ➢ ➢

GXe mixed with GAr, heated, and injected into the liquid at ~150 psi Increments of 20 ppm (by volume) Time structure determined using same deconvolution procedure Time-dependent structure of the LAr+Xe signal

➢ ➢ ➢

Cumulative scintillation signal from LAr+Xe

Prompt signal diminished 1.5 μs tail replaced by broad signal at ~150 ns (20 ppmv) Broad signal becomes more prompt as concentration increases

D. Whittington - DUNE Photon Detection - LIDINE 2015

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Conclusions ➢

Lots of progress developing a light guide photon detector for the DUNE LAr TPC Variety of designs have been explored Successful performance comparison tests SiPM readout quite promising for LAr operation Several TPC+PD tests on the horizon

➢ ➢ ➢ ➢



Big effort with thanks to many folks ➢

Indiana U. ●



Louisiana State U. ●



Janet Conrad, Matt Toups, Taritree Wongjirad, Len Bugel







Norm Buchanan, Dave Warner, Dylan Adams, Jay Jablonski, Tom Cummings, Forrest Craft, Andrea Shacklock

D. Whittington - DUNE Photon Detection - LIDINE 2015



Gary Drake, Patrick De Lurgio, Andrew Kreps, Michael Oberling, John T. Anderson, Zelimir Djurcic, Himansu Sahoo, Victor Guarino

Fermilab ●

Colorado State U.

Thomas Kutter, Jonathan Insler

Argonne Natl. Lab

MIT ●



Stuart Mufson, Jim Musser, Jon Urheim, Mark Gebhard, Brice Adams, Mike Lang, Brian Baugh, Paul Smith, Bryan Martin, Bruce Howard, Jonathon Lowery



Brian Rebel, Stephen Pordes, Marvin Johnson, Ron Davis, Bill Miner, Michael Geynisman

(And many others!) 28 August 2015

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Backup

D. Whittington - DUNE Photon Detection - LIDINE 2015

28 August 2015

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LAr Scintillation in a DUNE Single-Phase TPC

Scintillation from de-excitation of argon molecular state ➢

128 nm UV, two components ➢ ➢



Prompt (singlet state) signal (τ ~ 6 ns) Slow (triplet state) signal (τ ~ 1.5 μs)

Photon signal gives t0 for transverse position determination ➢



Calculate drift distance from time of arrival and known drift velocity in TPC E-field Resolution of < 100 ns easily attainable

14.4 m

12 m



3.6 m 58 m Steel Steel Cryostat Cryostat

Important for non-beam events ➢ ➢ ➢ ➢



Proton decay events Atmospheric neutrinos Supernova burst neutrinos Cosmic ray rejection

Electron energy resolution

SN burst neutrino spectrum

Resolution (%)



Particle identification/discrimination ➢

Ratio of prompt to total light depends on ionization density of track

D. Whittington - DUNE Photon Detection - DPF 2015

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Continuing Photon Detector R&D ➢

DUNE Far Detector simulation development (ongoing)



Current TallBo testing (summer 2015) ➢



Direct comparisons of baseline design with all four alternatives

35-ton Phase 2 (winter 2015) ➢



Estimate sensitivity of various photon detector system configurations to physics events (proton decay, SN, etc.)

Visibility



First test of light guide photon detectors in APA coupled with single-phase TPC

CERN single-phase TPC prototype (2018) ➢ ➢ ➢

Down-selected photon detector design deployed in single-phase TPC New charged particle beam in CERN north area Comparisons to WA105 dual-phase TPC performance

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