Costs and Scaling and a detector design

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Costs and Scaling(and a detector design)

• Maury Goodman
• Argonne National Lab
• May 1, 2003

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Outline

• Strategy
• Scaling/comparing Costs
• Design of a segmented detector
• Next Steps

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An Argument about q13

• Costs Timing --- How we got started
• Proposed off-axis experiments
• (NuMI, JPARCn) 200M
• If q13?0, we need more than one experiment due to
  degeneracies (CP, matter, p/4- q23,
  uncertainties,)
• If q130, we only need one experiment (next).

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Q13 from reactors?

• P(ne?ne) 1
• cos4q13 sin2 2q12 sin2(Dm212 L/4E)
• - sin2 2q13 sin2 (Dm2atm L/4E)
• (Ignores CP)
• (Ignores matter)

solar
P
atmospheric
L/E(km/MeV)
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Consequence of degeneracies
One set of measurements ? eight values of
q13
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• Costs

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Costs (from M. Shaevitz)
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Physics vs costs1

• Scale cost of Chooz (10M) vs detector size
• (Bemporad?1M)
• 10km, 1.0km, 0.7km
• Stats only
• Comparable to 1-6 Shaevitz estimates
• Looks promising

10km
1.0km
0.7km
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Better scaling

• First estimate was rate only now use Reynas
  calculations for sensitivity
• Scale to Chooz rates _at_ 2 Million each
• Two detectors
• Should add offset (didnt)
• Need to start thinking in Gigawatt-ton-years

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Costs (better)
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• For better costs need detector design
• ??Workshop
• Work on an alternative design

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Segmented or Monolithic?

• Could get away from most systematic errors with 2
  detectors
• Could improve error from detector mass with
  segmented detectors
• Lower but hopefully better understood
  efficiencies
• Energy scale/calibration becomes crucial

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Systematic Breakdown
25 _at_ 15m Signal/Background 2.2 _at_ 40m 0.7 _at_
95m
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Vertex Distribution of neutron capture from muon
spallation events
agrees to within 4.06 of expectation
total uncertainty in target mass 4.58
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More Systematics
Sin22?13 sensitivity
Sin22?13 sensitivity
Bin-to-bin uncorrelated
From hep-ph/0303232
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Design of a segmented detector

• My guess is a monolithic detector is preferable.
  
• By simultaneously designing and costing a
  segmented detector
• Have a backup
• Better understand systematics
• Better understand costs

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Straw Man modular detector

• 6 m3 solid scintillator
• Strips 4cm x 2cm x 6m
• 2 fibers per strip
• Gd paper between layers
• 2 ended readout
• 60,000x2 fiber ends
• 2 fibers/pixel
• 216 ton (total)
• 1000 M64s

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Strip design
Two fibers per strip Leave gaps for stability,
easier to achieve tolerances
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Modularity

• Make light tight in one cubic meter segments
• Managable to

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Fiducial Volume

• 4x4x4 out of 6x6x6?
• Inside pieces shorter
• Get cables out
• Orientation of plugs?

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Early thoughts on Electronics

• 100 ns timing
• 8 bit dynamic range
• Multi-anode M64s
• Looking for gt1pe signals
• Sum whole detector, timestamp
• Let the dynode trigger the digitization
• Further multiplexing may give savings

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Electronics
Components from Gary Drake
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Reactor Neutrino Experiment Conceptual Design of
Base Electronics
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Reactor Neutrino Experiment
Signal Acquisition Timing
Discriminate Events of Interest Above Dark Noise
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Second Crack at Straw Detector Costs

• 1000 Phototubes 1.3 M
• Readout (100 60K) 6.0
• Scintillator (5/kg) 1.1
• Fiber 1.0
• Gd sheets 0.1
• Veto counter 2.0
• Structure 1.0
• Source tubes 0.1
• Installation 0.4
• Total 13.0M
  unloaded per detector no
  site/tunnel

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Fiber Gluing
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Calibration

• Calibrate, Calibrate, Calibrate
• Map response
• Source tubes to calibrate in place
• Cosmic muons to calibrate in place
• Light injection system

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Mapping
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Relative Strip Response

• Relative LO 179,000 strip ends
• (compared to strips of the same type)
• Gaussian fit s 11
• 290 damaged or 0.16

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Thoughts on structure

• Need to make 3rd D smaller for fidvol?
• Veto 4-pi?

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• NEXT Steps

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From Workshop

• Collect software?
• Decide to pursue or drop segmented detector
• Redo cost scaling

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Detector

• Calculate detector response and required
  calibration accuracy
• Understand 3D problems
• Backgrounds/trigger issues?
• Design both detectors for white paper

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Some Issues

• Two detectors or Three?
• (size, design, overburden, site)
• Simultaneously understand budget
  drivers/physics/politics/schedules
• Get into funding consciousness of funding
  agencies (trip to DC?)
• We will say we are complementary to off-axis, but
  in some sense we are an alternative.

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Conclusions

• Its conceivable to get the desired sensitivity
  for 50M or less
• Need to understand systematic limitations
• Too late for Orbach list, need to get into
  funding consciousness
• If q13 is really right around the corner, great
  opportunity for first measurement.
• Grist for a white paper