Working Towards Large Area,
Picosecond-Level Photodetectors*
Erik Ramberg
Fermilab
Anti-Proton Workshop
22 May, 2010
* Thanks to Matthew Wetstein (ANL/EFI), Henry Frisch (EFI),
Mike Albrow (FNAL) and Anatoly Ronzhin (FNAL)
LAPPD Collaboration: Large Area Picosecond Photodetectors
Time-of-flight (TOF) in Particle Physics
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Particle identification in High
Energy Physics is as important as
ever, for investigating flavor
physics and rare processes.
Traditionally, Cerenkov detectors
have outperformed TOF for
energies above 2 GeV.
Typical TOF resolution (100
picoseconds) has been dominated
by physical size of signal
generation (cm size of dynode
structures) and inherent time scale
of scintillation.
100 picoseconds = 3 cm
5 picoseconds = 1.5 mm
E. Ramberg/Fast Timing at
Fermilab Test Beam/TIPP09
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LAPPD Collaboration: Large Area Picosecond Photodetectors
What If?
Large Water-Cherenkov Detectors will likely be a part of future longbaseline neutrino experiments.
What if we could build cheap,
large-area MCP-PMTs:
• ~ 100 psec time resolution.
• ~ mm-level spatial resolution.
• With close to 100% coverage.
• Cost per unit area comparable to
conventional PMTs.
How could that change the next-gen WC Detectors?
• Could these features improve background rejection?
• In particular, could more precision in timing information combined with better coverage
improve analysis?
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Detector Prescription (Generic)
• Small feature size needed
(reminder: 300 microns = 1 psec)
• Homogeneity
the ability to make uniform large-areas (think solarpanels, floor tiles, 50”-HDTV sets)
• Intrinsic low cost
Although application specific, you need low-cost
materials and robust batch fabrication. Needs to be
simple.
-> Micro-channel plate photo multipliers
(MCP/PMT) are our weapon of choice
4/8/2015
LAPPD Collaboration: Large Area Picosecond Photodetectors
The LAPPD Collaboration
Large Area Picsecond Photodetector Collaboration
John Anderson, Karen Byrum, Gary Drake, Henry Frisch, Edward May, Alexander Paramonov, Mayly
Sanchez, Robert Stanek, Robert G. Wagner, Hendrik Weerts, Matthew Wetstein, Zikri Zusof
High Energy Physics Division, Argonne National Laboratory, Argonne, IL
Bernhard Adams, Klaus Attenkofer, Mattieu Chollet
Advanced Photon Source Division, Argonne National Laboratory, Argonne, IL
Zeke Insepov
Mathematics and Computer Sciences Division, Argonne National Laboratory, Argonne, IL
Mane Anil, Jeffrey Elam, Joseph Libera, Qing Peng
Energy Systems Division, Argonne National Laboratory, Argonne, IL
Michael Pellin, Thomas Prolier, Igor Veryovkin, Hau Wang, Alexander Zinovev
Materials Science Division, Argonne National Laboratory, Argonne, IL
Dean Walters
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Funded by DOE and NSF
4 National Labs
5 Divisions at Argonne
3 US small companies;
Electronics expertise at Universities of
Chicago and Hawaii
Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL
David Beaulieu, Neal Sullivan, Ken Stenton
Arradiance Inc., Sudbury, MA
Sam Asare, Michael Baumer, Mircea Bogdan, Henry Frisch, Jean-Francois Genat, Herve Grabas,
Mary Heintz, Sam Meehan, Richard Northrop, Eric Oberla, Fukun Tang, Matthew Wetstein, Dai
Zhongtian
Enrico Fermi Institute, University of Chicago, Chicago, IL
Erik Ramberg, Anatoly Ronzhin, Greg Sellberg
Fermi National Accelerator Laboratory, Batavia, IL
James Kennedy, Kurtis Nishimura, Marc Rosen, Larry Ruckman, Gary Varner
University of Hawaii, Honolulu, HI
Robert Abrams, valentin Ivanov, Thomas Roberts
Muons, Inc., Batavia, IL
Jerry Va’vra
SLAC National Accelerator Laboratory, Menlo Park, CA
Oswald Siegmund, Anton Tremsin
Space Sciences Laboratory, University of California, Berkeley, CA
Dimitri Routkevitch
Goals:
• Exploit advances in material science
and nanotechnology to develop new,
batch methods for producing cheap,
large area MCPs.
• To develop a commercializable
product on a three year time scale.
Synkera Technologies Inc., Longmont, CO
David Forbush, Tianchi Zhao
Department of Physics, University of Washington, Seattle, WA
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Detector Development- 3 Prongs
MCP development: use modern fabrication processes to control
emissivities, resistivities, out-gassing
Use Atomic Layer Deposition for emissive material. Amplification on
cheap inert substrates (glass capillary arrays, AAO). Scalable to large
sizes, economical, chemically robust and stable.
Readout: use transmission lines and modern chip technologies for
high speed cheap low-power high-density readout.
Anode is a 50-ohm stripline, scalable up to many feet in length.
Readout 2 ends; CMOS sampling onto capacitors- fast, cheap, lowpower
Simulation: use computational advances to make design choices.
Modern computing tools allow simulation at level of basic processesvalidate with data.
4/8/2015
Application 1-Energy Frontier
At colliders we measure the 3-momenta of hadrons, but can’t follow the flavor-flow of
quarks, the primary objects that are colliding. 2-orders-of-magnitude in time resolution
would allow us to measure ALL the information=>greatly enhanced discovery potential.
Specs:
Signal: 50-10,000
photons
Space resolution: 1 mm
Time resolution 1 psec
Cost: <100K$/m2:
t-tbar -> W+bW-bbar at CDF
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Application 2- Lepton Flavor Physics
LAPPD Collaboration: Large Area Picosecond Photodetectors
Application 2 - Intensity Frontier
• Example- DUSEL detector with 100% coverage and 3D photon
vertex reconstruction.
• Need >10,000 square meters!
• Spec: single photon sensitivity, 100 ps time, 1 cm space, low
cost (5-10K$/m2)
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Application 3- Medical Imaging (PET)
Depth of interaction measurement currently has best
value of 375 ps (1 cm) resolution (H. Kim, UC).
Spec: signal 10,000 photons,30 ps time, 1 mm space,
30K$/m2, MD-proof
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LAPPD Collaboration: Large Area Picosecond Photodetectors
PET
(UC/BSD,
UCB, Lyon)
Parallel. Efforts on
Specific Applications
Collider
(UC,
ANL,SLAC,.
.
LAPPD Detector
Development
ANL,Arradiance,Chicago,Fermil
ab,
Hawaii,Muons,Inc,SLAC,SSL/U
CB, Synkera, U. Wash.
DUSEL
K->pnn
(Matt,
Mayly, Bob,
John, ..)
Drawing Not To Scale (!)
(UC(?))
Security
(TBD)
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Anatomy of an MCP-PMT
1.
2.
3.
4.
5.
Photocathode
Multichannel Plates
Anode (stripline) structure
Vacuum Assembly
Front-End Electronics
Conversion of photons to electrons.
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Anatomy of an MCP-PMT
1.
2.
3.
4.
5.
Photocathode
Microchannel Plates
Anode (stripline) structure
Vacuum Assembly
Front-End Electronics
Amplification of signal. Consists of two
plates with tiny pores (~10 microns), held at
high potential difference.
Initial electron collides with pore-walls
producing an avalanche of secondary
electrons. Key to our effort.
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Anatomy of an MCP-PMT
1.
2.
3.
4.
5.
Photocathode
Microchannel Plates
Anode (stripline) structure
Vacuum Assembly
Front-End Electronics
Charge collection. Brings signal out of
vacuum.
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Anatomy of an MCP-PMT
1.
2.
3.
4.
5.
Photocathode
Microchannel Plates
Anode (stripline) structure
Vacuum Assembly
Front-End Electronics
Maintenance of vacuum. Provides
mechanical structure and stability to the
complete device.
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Anatomy of an MCP-PMT
1.
2.
3.
4.
5.
Photocathode
Microchannel Plates
Anode (stripline) structure
Vacuum Assembly
Front-end electronics
Acquisition and digitization of the signal.
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Channel Plate Fabrication
Conventional MCP Fabrication
• Pore structure formed by drawing and
slicing lead-glass fiber bundles. The glass
also serves as the resistive material
• Chemical etching and heating in hydrogen
to improve secondary emissive properties.
• Expensive, requires long conditioning, and
uses the same material for resistive and
secondary emissive properties. (Problems
with thermal run-away).
Proposed Approach
• Separate out the three functions
• Hand-pick materials to optimize
performance.
• Use Atomic Layer Deposition (ALD):
a cheap industrial batch method.
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Front-end Electronics/Readout
Waveform sampling ASIC
Electronics Group: Jean-Francois Genat, Gary Varner, Mircea
Bogdan, Michael Baumer, Michael Cooney, Zhongtian Dai, Herve
Grabas, Mary Heintz, James Kennedy, Sam Meehan, Kurtis
Nishimura, Eric Oberla, Larry Ruckman, Fukun Tang (meets weekly)
Have to understand
signal and noise in the
frequency domain
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Front End Electronics
• Collaboration between U of Chicago and Hawaii.
• Resolution depends on # photoelectrons, analog bandwidth,
and signal-to-noise.
• Transmission Line: readout both ends  position and time
• Cover large areas with much reduced channel count.
• Simulations indicate that these transmission lines could be
scalable to large detectors without severe degradation of
resolution.
Wave-form sampling is best, and can
Differential time resolution between
be implemented in low-power widely
two ends of a strip line
available CMOS processes (e.g. IBM
8RF). Low cost per channel.
First chip submitted to
MOSIS -- IBM 8RF (0.13
micron CMOS)- 4-channel
prototype. Next chip will
have self-triggering and
phase-lock loop
J-F. Genat, G. Varner, M. Bogdan, M. Baumer, M. Cooney, Z.
Dai, H. Grabas, M. Heintz, J. Kennedy, S. Meehan, K. Nishimura,
E. Oberla, L.Ruckman, F. Tang
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Collaboration: Large Area Picosecond Photodetectors
Photonis LAPPD
Planicon
on Transmission Line Board
Couple 1024 pads to strip-lines with silver-loaded epoxy
(Greg Sellberg, Fermilab).
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Simulation
• Working to develop a firstprinciples model to predict MCP
behavior, at device-level, based
on microscopic parameters.
Transit Time Spread (TTS)
• Will use these models to
understand and optimize our
MCP designs.
Z. Yusov, S. Antipov, Z. Insepov (ANL),
V. Ivanov (Muons,Inc), A. Tremsin (SSL/Arradiance),
N. Sullivan (Arradiance)
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Scaling Performance to Large Area
Anode Simulation(Fukun Tang)
• 48-inch Transmission Line- simulation shows 1.1
GHz bandwidth- still better than present electronics.
KEY POINT- READOUT FOR A 4-FOOT-WIDE
DETECTOR IS THE SAME AS FOR A LITTLE ONEHAS POTENTIAL…
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Mechanical Assembly
Rich Northrop, Dean Walters, Joe Gregar Bob Wagner, Michael
Minot, Jason McPhate, Ossy Siegmund
8” proto-type stack
design sketch
8” proto-type mock-up
BNL Colloquium
4/8/2015
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LAPPD Collaboration: Large Area Picosecond Photodetectors
The 24”x16” `SuperModule
Tile now has no
penetrations- neither HV
nor signals
Digital card in design
Front-end ASICs ditto
Mockup of 1x3 ½ SM
Real glass parts
Electrical tests in air in situ
about to begin
BNL Colloquium
4/8/2015
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Channel Plate Fabrication w/ ALD
pore
1.
Start with a porous, insulating
substrate that has appropriate
channel structure.
1 KV
Alternative ALD Coatings:
borosilicate glass filters
(default)
Anodic Aluminum Oxide (AAO)
2.
Apply a resistive coating (ALD)
3.
Apply an emissive coating (ALD)
4.
Apply a conductive coating to the
top and bottom (thermal
evaporation or sputtering)
Al2O3
Conventional MCP’s:
SiO2
(ALD SiO2 also)
MgO
ZnO
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LAPPD Collaboration: Large Area Picosecond Photodetectors
Status After Several Months
• Using our electronic front-end and
striplines with a commercial Photonis
MCP-PMT, were able to achieve 1.95
psec differential resolution, 97 µm
position resolution (158 photoelectrons).
• Demonstrated ability produce 33 mm
ALD coated channel-plate samples.
• Development of advanced testing
capabilities underway.
• Preliminary results at APS show
amplification in a commercial MCP after
ALD coating.
• Growing collaboration between
simulation and testing groups.
B. Adams, M. Chollet (ANL/APS),
M. Wetstein (UC, ANL/HEP)
• After characterizing the Photonis MCP, we coat the
plates with 10 nm Al2O3.
• The “after-ALD” measurements have been taken
without scrubbing.
• These measurements are ongoing.
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Beam line time-of-flight
for particle
identification
LAPPD Collaboration:
Large Area Picosecond
Photodetectors
Testing the Photek 240 MCP/PMT in
Fermilab’s Test Beam
at + 7m far
position
B
8 GeV/c
p or π
VETO L+R
C = PMT210
reference
B
A
TRIG L*R
SiPM’s also an option and were tested.
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Some
Results:
LAPPD Collaboration:
Large Area Picosecond Photodetectors
Test Beam Results for 120 GeV monoenergetic
protons beam on quartz bar detector
Remove tails of PH distributions
(correlated, probably interactions)
Apply time-slewing correction
(CFD needs residual PH correction)
Fit Dt = (t1 – t2) to Gaussian:
channels
sDt = 16 ps, which means each device contributes 11 ps
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Positive 8 GeV/c
beam over
7 m:
LAPPD Collaboration:
Large Area
Picosecond Photodetectors
Test Beam Results for 7 meter separation in 8 GeV
mixed (muons, pions, protons, electrons) beam
π
p
Proton content of beam gives 146 ps difference
Resolution of timing difference σ = 7 ch = 21.7 ps
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(No corrections for slewing etc)
LAPPD Collaboration: Large Area Picosecond Photodetectors
Conclusions
• The large area, fast timing photodetector project is an advanced
cooperative research project, headed up by U. Chicago, and highly
supported by the DOE. We’re on a 3 year time table. Lots of work ahead.
Preliminary achievements are encouraging.
• The cooperation between quite different research areas (materials science,
space science, high energy physics, medical imaging) is striking and is
perhaps a model for future endeavors.
• If successful, this project presents potential opportunities for future water
Cherenkov detectors, collider detectors, fixed target detectors, medical
imaging, etc.
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