The Development of Large-area Detectors With Space and Time Resolution

1
The Development of Large-area Detectors With
Space and Time Resolution

• Henry J. Frisch
• Enrico Fermi Institute and Argonne Natl. Lab.

• OUTLINE
• Application Space Four frontiers- time
  resolution, area, QE, and cost (different
  applications sit at different points in this 4D
  space, but not separated by large amounts of
  development effort- all 4 are fertile.)
• Goals of 3-year RD effort- commercializable
  modules
• The LAPD Collaboration present status
• Status and needs of bridging the neutrino world
  to the hardware RD effort.

2
Model of LAPD Interface to Applications

• Question- how to interface to the specific needs
  of the different applications while focusing our
  resources and facilities on the basic RD needed?
• Answer- build interfaces to each of the
  applications so that in each case there is a
  group in the application field working closely
  with the technical developers. Fertile area for
  new ideas, designs, applications. (great for
  young folks looking for a leadership role in
  their field).
• Best example so far is Medical Imagining- have a
  group at UC who has worked closely with us also
  the French connection through Patrick LeDu. A
  similar effort has been started with the neutrino
  community- Mayly Sanchez, Matt Wetstein, John
  Felde, and Bob Svoboda.

3
Parallel Efforts on Specific Applications

• .

Drawing Not To Scale (!)
LAPD Detector Development
ANL,Arradiance,Chicago,Fermilab,
Hawaii,Muons,Inc,SLAC,SSL/UCB, Synkera, U. Wash.
4
Application 1 (my initial motivation)
We (you, we_all) spend big bucks/year measuring
the 3-momenta of hadrons, but cant follow the
flavor-flow of quarks, the primary objects that
are colliding. Principle measure ALL the
information
CDF-1979 to present
Discoveries Top quark B_s Mixing Measurements Ma
ny many many- and many more not done yet
Not light compared to Atlas and CMS ( 5000 tons)
5
Is Flavor Fundamental?

• Is the existence of flavor- e,mu, tau up,
  down, strange, charm, bottom, and top,
  fundamental, in the sense that if we cant
  understand it in a deeper way, were in the grip
  of initial conditions rather than fundamental
  symmetries or principles?
• Really a deep divide between the string landscape
  community, who are stuck with 10500 equally
  possible universes, and us, who have this one
  characterized by small integers and interesting
  patterns. (Aside- This latter, I believe, is the
  future area for Fermilab).

6
Quarks and Lepton Sectors-Fundamental??
M2 MeV
Q2/3
M175,000 MeV
M1750 MeV
Quarks
M300 MeV
M4,500 MeV
Q-1/3
Nico Berry (nicoberry.com)
(Should we ask for one for the neutrinos? What do
they look like? Inverted or Normal?)
M2 MeV
7
Application 1-Quark Flavor Physics

• E.g- Tevatron 3rd-generation detector (combine D0
  and CDF hardcore groups) ATLAS Upgrade (true
  upgrade)
• One example- precision measurements of the top
  and W masses

8
A real CDF Top Quark Event
T-Tbar -gt WbW-bbar
W-gtcharm sbar
Measure transit time here (stop)
B-quark
T-quark-gtWbquark
T-quark-gtWbquark
B-quark
Cal. Energy From electron

• Fit t0 (start) from all tracks

W-gtelectronneutrino
Can we follow the color flow through kaons, cham,
bottom? TOF!
9
Application 1a- Collider Detector UpgradesPhoton
Vertexing

• Real data- 3 events in one beam crossing
• 2 events at same place 2 at same time
• Can distinguish in the 2D space-time plane

10
Application 2- Lepton Flavor Physics
Constantinos Melachrinos (Cypress) (idea of
Howard Nicholson)

• Example- DUSEL detector with 100 coverage and 3D
  photon vertex reconstruction.
• Need gt10,000 square meters (!) (100 ps resolution)

11
Application 3- Medical Imaging (PET)
Advantages Factor of 10 cheaper (?) depth of
interaction measurement 375 ps resolution (H.
Kim, UC)
12
Application 4 Fixed-target GeometriesParticle
ID and Photon Vertexing
Geometry is planar- i.e. the event is projected
onto a detection plane. Timing gives the path
length from the point on the plane to the
interaction. New information for vertexing,
reconstruction of p0 s from 2 photons, direction
of long-lived particles. Very thin in
zdirection, unlike Cherenkovcounters. Can give
a space-point with all 3 coordinates- x,y and
z Key new information- gives tomographic
capability to a plane
Thin Pb Converter
13
Application 5- Nuclear Non-proliferation
Havent thought about this yet- looking for
interested ANL folks. But

1. MCPs loaded with Boron or Gadolinium are used as
   neutron detectors with good gamma separation
   (Nova Scientific).
2. Large-area means could scan trucks, containers
3. Time resolution corresponds to space resolution
   out of the detector plane IF one has a t_0

An area for possible applications- needs a leader
to form an application group.
14
Why has 100 psec been the for 60 yrs?
Typical path lengths for light and electrons are
set by physical dimensions of the light
collection and amplifying device.
These are now on the order of an inch. One inch
is 100 psec. Thats what we measure- no surprise!
(pictures from T. Credo)
Typical Light Source (With Bounces)
Typical Detection Device (With Long Path Lengths)
15
Characteristics we need

• Small feature size ltlt 300 microns
• Homogeneity (ability to make uniform large-area-
  think solar-panels, floor tiles)
• Fast rise-time and/or constant signal shape
• Lifetime (rad hard in some cases)
• Intrinsic low cost application specific
  (low-cost materials and simple batch fabrication)

16
Our Detector Development- 3 Prongs

• Readout Transmission lineswaveform sampling
• Anode is a 50-ohm stripline- can be long
  readout 2 ends
• CMOS sampling onto capacitors- fast, cheap,
  low-power
• Sampling ASICs demonstrated and widely used
• Go from .25micron to .13micron 8ch/chip to
  32/chip
• Simulations predict 2-3 ps resolution with
  present rise times, 1 with faster
• (MCP Signal Processing for Pico-second
  Resolution Timing Measurements.Jean-Francois
  Genat (Chicago U., EFI) , Gary Varner (Hawaii U.)
  , Fukun Tang, Henry J. Frisch (Chicago U., EFI) .
  Oct 2008. 18pp. Published in Nucl.Instrum.Meth.A6
  07387-393,2009. e-Print arXiv0810.5590 )
• MCP development
• Use Atomic Layer Deposition for emissive
  materials (amplification) passive substrates
• Simulation of EVERYTHING as basis for design
• Modern computing tools plus some amazing people
  allow simulation of things- validate with data.

17
Generating the signal (particles)

• Use Cherenkov light - fast

Incoming rel. particle
Custom Anode with Equal-Time Transmission Lines
Capacitative. Return
A 2 x 2 MCP- actual thickness 3/4 e.g. Burle
(Photonis) 85022-with mods per our work
Collect charge here-differential Input to 200 GHz
TDC chip
18
Micro-channel Plates

• Currently the glass substrate has a dual
  function-
• To provide the geometry and electric field like
  the dynode chain in a PMT, and
• To use an intrinsic lead-oxide layer for
  secondary electron emission (SEE)

Micro-photograph of Burle 25 micron tube- Greg
Sellberg (Fermilab)- 2M/m2- not including
readout
19
Get position AND timeAnode Design and
Simulation(Fukun Tang)

• Transmission Line- readout both endsgt pos and
  time
• Cover large areas with much reduced channel
  account.

20
Photonis Planicon on Transmission Line Board

• Couple 1024 pads to strip-lines with
  silver-loaded epoxy (Greg Sellberg, Fermilab).

21
Comparison of measurements (Ed May and
Jean-Francois Genat and simulation (Fukun Tang)

• Transmission Line- simulation shows 3.5GHz
  bandwidth- 100 psec rise (well-matched to MCP)
• Measurements in Bld362 laser teststand match
  velocity and time/space resolution very well

22
Scaling Performance to Large AreaAnode
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 ONE- HAS POTENTIAL

23
Proof of Principle

• Camden Ertley results using ANL laser-test stand
  and commercial Burle 25-micron tube- lots of
  photons
• (note- pore size may matter less than current
  path!- we can do better with ALD custom designs
  (transmission lines))

24
Understanding the contributing factors to 6 psec
resolutions with present Burle/Photonis/Ortec
setups- Jerry Vavras Numbers

1. TTS 3.8 psec (from a TTS of 27 psec)
2. Cos(theta)_cherenk 3.3 psec
3. Pad size 0.75 psec
4. Electronics (old Ortec) 3.4 psec

25
ANL Test-stand Measurements
Jean-Francois Genat, Ed May, Eugene Yurtsev

• Sample both ends of transmission line with
  Photonis MCP (not optimum)

2 ps 100 microns measured
26
The Large-Area Photo-detector Collaboration
Have formed a collaboration to do this in 3
years. 4 National Labs, 5 Divisions at Argonne, 3
companies, electronics expertise at UC and
Hawaii RD- not for sure, but we see no
show-stoppers (yet)
27
Large-area Micro-Channel Plate Panel Cartoon
N.B.- this is a cartoon- working on workable
designs-
Front Window and Radiator
Photocathode
Pump Gap
Low Emissivity Material
High Emissivity Material
Normal MCP pore material
Gold Anode
50 Ohm Transmission Line
Rogers PC Card
Capacitive Pickup to Sampling Readout
28
Cartoon of a frugal MCP

• Put all ingredients together- flat glass case
  (think TVs), capillary/ALD amplification,
  transmission line anodes, waveform sampling

29
Can dial size for occupancy, resolution- e.g.
neutrinos 4by 2
30
MCP Simulation

• Zeke Insepov (MCSD) and Valentin Ivanov
  (Muons,Inc)

31
MCP Simulation

• Zeke Insepov (MCSD) and Valentin Ivanov
  (Muons,Inc)

32
MCP Simulation

• Zeke Insepov (MCSD) and Valentin Ivanov
  (Muons,Inc)

33
MCP Simulation

• Zeke Insepov (MCSD) and Valentin Ivanov
  (Muons,Inc)

34
Incom glass capillary substrate

• New technology- use Atomic Layer Deposition to
  functionalize an inert substrate- cheaper, more
  robust, and can even stripe to make dynode
  structures (?)

35
Another pore substrate (Incom)
36
Self-Assembled Passive Substrates

• Self-assembled material- AAO (Anodic Aluminum
  Oxide)- Hau Wang (MSD)

37
Functionalization- ALD

• Jeff Elam, Thomas Prolier, Joe Libera (ESD)

38
Functionalization- ALD

• Jeff Elam, Thomas Prolier, Joe Libera (ESD)

39
Mechanical Assembly

• Difficult issues
• sealing a large flat panel object
• Assembly- can we avoid vacuum assembly? (I think
  yes)
• Sealed-tube clean living- outgassing, scrubbing,
  surface-physics chemical interactions with
  photo-cathode
• Cost (a driver)

40
Mechanical Assembly
41
Mechanical Assembly

• 8 proto-type stack
• Design sketch

8 proto-type mock-up
42
Mechanical Assembly
Luckily we have access to the worlds most
sophisticated test facilities at Argonne and UC

• 8 proto-type- stresses

Lead bricks
43
Front-end Electronics/Readout Waveform sampling
ASIC
First have to understand signal and noise in the
frequency domain
EFI Electronics Development Group Jean-Francois
Genat (Group Leader) and Hawaii (Gary Varner
group)
44
Front-end Electronics

• Resolution depends on 3 parameters
• Number of PEs
• Analog Bandwidth
• Signal-to-Noise

• Wave-form sampling does well- CMOS (!)

45
Front-end Electronics

• Wave-form sampling does well - esp at large Npe

46
Front-end Electronics-II

• See J-F Genat, G. Varner, F. Tang, and HF
• arXiv 0810.5590v1 (Oct. 2008)- to be published
  in Nucl. Instr. Meth.

47
Front-end Electronics/Readout Waveform sampling
ASIC
Chicago/Hawaii collaborative effort Gary Varner
Hawaii group J.F. Genat, Herve Grabas, Eric
Oberla, Sam Meehan, Mary Heintz (EFI)

• Varner, Ritt, DeLanges, and Breton have
  pioneered waveformsampling onto an array of
  CMOS capacitors.

48
First 0.13micron ASIC submitted 2 wks ago (!)
The chip submitted to MOSIS -- IBM 8RF (0.13
micron CMOS)- 4-channel prototype. Plan on 16
channels/chip- possibly 32 later.
49
Returning to Neutrino Physics
Constantinos Melachrinos (Cypress) (idea of
Howard Nicholson)

• Example- DUSEL detector with 100 coverage and 3D
  photon vertex reconstruction.
• Need gt10,000 square meters (!) (100 ps resolution)

50
Neutrino-Detector Specific Considerations

• Photo-cathode spectral response

Time dispersion is steep in the blue- also the
response will be more dependent on distance in
the blue. What is the optimal photo-cathode
spectral response?

• Notes (HJF opinions- nobody elses fault)
• III-V or nano-structured photo-cathodes may be
  much easier and cheaper to assemble- will test
  pure gas assembly for both bialkalis and III-V.
• And may be much more robust long-term
• Trade-off is between photons and
  dispersion/attenuation
• Cannot be answered without a real simulation
  INCLUDING track reconstruction (Matt, John, Bob,
  )

51
Neutrino-Detector Specific Considerations

• Photo-cathode Quantum Efficiency

From the June photo-cathode workshop it seems
plausible that there are big factors to be gained
in total QE (anti-reflection, opaque
photo-cathodes, funnel geometries, nano-scale
materials, active pumping, )

• Notes (HJF opinions- nobody elses fault)
• Basic physics of photon absorption, energy
  transfer, electron emission is rich and fertile
  for new ideas- e.g. see, e.g. Greg Engels talk
  at the workshop for sub-psec energy pumping in
  photo-cathodes (http hep.uchicago.edu/psec,
  followed by Library) 50-years from now can we
  do as well?
• Requires major investment in materials science
  facilities and expertese- not in HEP, but exist
  at Argonne, e.g.
• How does QE trade off vs coverage/cost in a
  conventional detector, or in tracking detector?
  (i.e. how much is QE worth?)

52
Neutrino-Detector Specific Considerations

• Single Photon Response and Time resolution

Time response will depend on being able to
reconstruct tracks- one very attractive goal is
to be able to resolve pizeros from electrons.
Scale is set by radiation length in water- 40 cm-
so if we can do 100 psec, 1 inch, can we tell 2
vertices from one, 4 electrons from 1 ?

• Notes (HJF opinions- nobody elses fault)
• Cannot be answered without a real simulation
  INCLUDING track reconstruction (Matt, John, Bob,
  )
• Affects choice of photo-cathode- may want to be
  in the red (see Jerry Vavras talk at the June
  Photo-cathode workshop- slides on psec web page
  (click on Library).
• Single photon response has its own detector
  considerations

53
Neutrino-Detector Specific Considerations

• Reconsidering Detector Aspect Ratio Constraints

Flat panels with load-bearing wall internal
construction may allow much higher pressures on
the front window, and should not fail
catastrophically as the volume inside is small.

• Notes (HJF opinions- nobody elses fault)
• Walls are cheaper to build underground than
  ceilings (30?)
• Larger coverage fraction allows larger
  fiducial/total ratio- smaller cavern for same
  fiducial volume
• Larger coverage fraction allows working closer to
  walls, gt can move towards rectangular book on
  binding (tall, deep, narrow) geometry with less
  loss of fiducial ratio.
• Tall-deep narrow geometry plus track
  reconstruction capability may also allow a
  transverse magnetic field (across the narrow) for
  lepton sign determination.

54
Status

• We have been funded for 3 years by DOE
• We have yet to be able to access the funds- but
  are within 1 mile of us. Many things are
  waiting for funds. We will, however, prevail
  (illegitumum non carborundum).
• We are going ahead in the meantime due to support
  from the Director and Mike Pellin and Harry
  Weerts- Im amazed by Argonnes strength and
  creativity and facilities!
• We have a blog and a web page- fun to look at and
  kibitz- http//hep.uchicago.edu/psec (dont be
  bullied by the blog).
• So far no show-stoppers (but show hasnt
  started)..

55
What would help us from the neutrino community

• Simulation of pizero/electron rejection at the
  vertex for different coverages, QEs, geometries
• Simulation of momentum resolution using track
  reconstruction in our parameter space
• Simulation(s) of performance vs QE
• Applications by grad students to our upcoming
  (hardware) graduate student fellowship program
• Ties to material science and engineering groups
  interested in secondary-electron and
  photo-electron processes
• Much more interchange and interaction

56
The End-
57
BACKUP
58
Photo-multiplier in a Pore

• Idea is to build a PMT structure inside each
  pore- have a defined dynode chain of rings of
  material with high secondary emissivity so that
  the start of the shower has a controlled geometry
  (and hence small TTS)
• One problem is readout- how do you cover a large
  area and preserve the good timing?
• Proposed solution- build anode into pores,
  capacitively couple into transmission lines to
  preserve pulse shape.

59
Jerrys s re-visited Solutions to get to
ltseveral psec resolution.

• TTS 3.8 psec (from a TTS of 27 psec)
• MCP development- reduce TTS- smaller
  pores, smaller gaps, filter chromaticity, ANL
  atomic-deposition dynodes and anodes.
• Cos(theta)_cherenk 3.3 psec
  
• Same shape- spatial distribution (e.g.
  strips and time-differences measure spot)
• 3. Pad size 0.75 psec-
  
  Transmission-line readout and shape
  reconstruction
• 4. Electronics 3.4 psec
  
  fast sampling- should be able to get lt 2
  psec (extrapolation of simulation to faster
  pulses)

60
Front-end Electronics/Readout Waveform sampling
ASIC
Herve Grabas
Herve Grabas, J.F. Genat, Gary Varner
61
FY-08 Funds ChicagoAnode Design and
Simulation(Fukun Tang)
62
What would TOFlt10psec do for you?

• (disclaimer- I know next to nothing about LHCb,
  b-physics, or the Collab. goals..- Im making
  this up.needs work- would be delighted to see
  someone pick this up.)

1. If you can stand a little active material in
   front of your em calorimeter, convert photons- 10
   psec is 3mm IN THE DIRECTION of the photon flight
   path- can vertex photons. Do pizeros, etas, KL
   and KS,
2. This allows all neutral signature mass
   reconstruction- new channels. e.g. the CP
   asymmetry in BS-gtp K0 (J.Rosner suggestion)
3. Etas in general are nice e.g. BS-gtJ/psi eta
   (again, J.R.)
4. With two planes and time maybe get to 1 psec,300
   microns along flight path- can one vertex from
   timing?
5. Searches for rare heavy long-lived things (other
   than bs)- need redundancy.
6. May help with pileup- sorting out vertices.