HighResolution TimeofFlight Spectrometer for Fast Neutrons

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High-Resolution Time-of-Flight Spectrometer for
Fast Neutrons
What ? Why ? How ? Who ?
Letter of Intent
JRA - Proposal Development of a next-generation
detection system for high-energy
neutron Performance goals - Very good
time-of-flight resolution (lt100 psec) - Good
spatial resolution (lt1 cm in all three
dimensions) - High detection efficiency (gt90) -
Good neutron recognition / multi-hit capabilities
Improving the R3B experimental facility at GSI
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The R3B facility _at_GSI
Mixed beam
Charged fragments
ToF, DE
LAND
tracking ? Br A/Qbg
Neutrons
ToF, x, y, z
12 m
projectile tracking
Photons
ALADIN large-acceptance dipole
Crystal Ball and Target
Beam
Excitation energy E from kinematically complete
measurement of all outgoing particles
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The Large Area Neutron Detector LAND
Efficiency
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Resolution sTof 250 ps sp
5 - 10 MeV/c sIVM 0.2 - 1. MeV
Nucl. Instr. Meth. A314 (1992) 136
Neutron Energy (MeV)
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Physics Motivation
What ? Why ? How ? Who ?

• A large number of physics programs (and users)
  will benefit
• (fragmentation beams,
  reaccelerated beams, gt50 A MeV)
• Some experiments critically depend on the
  improved performance
• - Inelastic excitation of radioactive nuclei
• elm excitation, multipole response, new
  collective modes
• - Quasi-free scattering
• in particular (p,pn) reactions, n
  detector at 45 degree ? resolution !!!
• single-particle structure,
  nucleon-nucleon correlations, in-medium effects
• - Astrophysical reaction rates
• (g,n) cross sections at very low
  excitation energy ? resolution !!!
  
• - Nuclear states beyond the driplines
• e.g. multi-neutron clusters
  ? multi-hit recognition capability !!!
• - The asymmetry energy and the nuclear/neutron
  Equation of State
• pygmy dipole, n-skin, neutron flow
  measurements ...
• - Kinematical complete measurements of fission
  and spallation reactions

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Research and Development Program
What ? Why ? How ? Who ?

• Idea Converter principle plus RPC based
  charged particle detection
• (modular detector, gt10000 channels, gt100
  m2 RPC)
• RPCs have been used for detection of
  minimum-ionizing
• 
  light charged particles
• Time resolution in the order of 50 psec
  has been reached
• Activities
• Understanding of the reaction mechanisms/hadronic
  shower properties and their simulation
• Simulation of possible detector concepts and
  their optimization
• Study of detections principles, alternatives to
  converter/charged-particle principle
• Detection of low-energy charged particles with
  RPCs (efficiency, resolution)
• Development of prototype modules and tests
• Development of a cost-effective readout scheme
  providing excellent time resolution
• Final deliverable Prototype (20 detector)

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Collaboration
What ? Why ? How ? Who ?

• Participants and Expertise
• GSI
• KVI Groningen
• ISS Bucharest
• Jagellonian University Krakow
• Universidad Santiago de Compostela
• CEA Saclay
• University Frankfurt
• University Mainz
• TU Darmstadt
• University Köln
• FZ Rossendorf
• Associated Partners Saha Institute, Kolkata
  Tokyo Institute of Technology

Collaboration will bring in manpower, laboratory
infrastructure, plus all investment costs