Current Status and Possible Items around

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Current Status andPossible Items around
neutrino beam
For discussion w/ Eric Zimmerman, 11/Mar/04

• Horn
• Target
• Remote maintenance tools
• Decay volume window and collimator
• muon monitor

Many items are still conceptual design stage.
Which item can be shared or brought to outside
collaborators is not yet clear. In this
note, some possible items are listed for the
first step of cooperation. Here, I assume
technical contribution (not financial one).
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Horn status-

• Proto-type for 1st horn inner conductor was
  ordered.
• Outer diameter is 60mm.
• Test w/ K2K outer conductor and power supply
  will be done.
• Cooling test set up for 1st horn inner
  conductor have arrived.
• Test of nozzle will be done.
• Stress Analysis
• 1st horn final(?) stress analysis will be done
  after we fix the nozzle design.
• 2nd and 3rd horn stress analysis was just
  started. Inner conductor shape
• will be optimized.

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J-PARC Neutrino Horn System
1st 2nd
3rd 320kA 320kA
320kA
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1st Horn Inner Conductor
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Cooling Test setup
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Horn Possible contribution items

• Cooling system test for 2nd and 3rd horns.
• Our set up is rather small system.
• Coupling of strip lines which can be
  coupled/decupled remotely.
• Coupling of water pipe which can be
  coupled/decupled remotely.
• Many know-how on parts from the MiniBooNE horn.
  (bolts, insulators.)
• (Remote) Alignment system
• required accuracy 1mm.

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Target current status

• Effect of radiation is being studied.
• 0.26 dpa/yr
• shrinkage, worse conductivity, swelling are
  problem.
• We have a one basic design w/ water cooling.
• Coaxial two water paths.
• However water cooling has problems.
• shrinkage inside container,
• pressure of instantaneous temperature rise of
  water
• Therefore, we started to think about He cooling.
• Can be operated at rather high temperature, hence
  lower radiation effect.
• Coaxial two flow paths.
• 30m/s _at_ 5 atm.
• For the compressor, we are onsulting cryo. group
  at IPNS, KEK
• Cooling path material
• Start basic designing w/ Al, Ti and C/C composite
• Insulator from horn(1kV)
• Start thinking about ceramics and plasma sprayed
  alumina.

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Remote Maintenance
Top View
Side View
Disconnect Horn and its support structure
including strip-lines. Is this realistic? Residual
radiation level should be checked. Anyway, we
need remotely connectable/dis-connectable
cuppling For strip-lines and water pipes.
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DV collimator
Need cooling Almost no work yet.
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DV window
Strategy If we put a DV window, it might be
broken by heat load. Cooling is also
problem. Since the target station will be filled
with He, DV window is not necessary during
operation. However, w/o window, each time we open
the target station, He inside DV must be
released. It will need time and cost. Therefore,
we are planning to make a movable window which
opens during operation and be closed during
maintenance at the target station. The window
must withstand the evacuation of the target
station and DV. The window must be installed from
upside.
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K2K DV window
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Muon Monitor
J. Kamda(KEK) has been working on muon monitor.
But he will move to ICRR. TRIUMF has an interest
on a diamond detector. In addition to these
solid detectors, ionization chamber should be
installed. For muon monitor, presentation by J.
Kameda at NBI is useful. ( http//www-ps.kek.jp/
nbi2003/presentation/index.html)