ADS experiments in Dubna

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ADS experiments in Dubna

• Mitja Majerle
• for the
• Energy Plus Transmutation
• collaboration

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What are Accelerator Driven Systems ?
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Accelerator Driven Systems

• Subcritical reactor
• Wider choice for reactor fuel (238U, 232Th)
• Transmutation of nuclear waste
• Increased safety
• Accelerator
• Protons or light ions of energy around 1 GeV
• Very high powers (tens, hundreds of MeW)
• Stability of the beam
• Spallation reaction

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Some projects on this topic

• C.Rubbia at CERN (protons on lead block)
• MUSE Cadarache (reactor keff0.95 with (d,t)
  source)
• TRADE Casaccia (reactor coupled with cyclotron)
• MEGAPIE at PSI (target research)

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Dubna research

• Until today
• cross-section measurements on 660 MeV protons
• Leadparafine (GAMMA-2)
• Lead target (PHASOTRON)
• Energy Plus Transmutation
• Lead in graphite block (GAMMA-MD)
• Future
• Subcritical Assembly Dubna (SAD)

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PHASOTRON experiment

• Lead target 660 MeV protons
• Activation detectors (Au, Al, Bi)
• 129I samples
• Focus spatial distribution of fast neutrons

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ENERGY PLUS TRANSMUTATION

• Lead target natU blanket
• Protons (0.7-2 GeV), deuterons (1.6-2.52 GeV)
• Activation detectors (Al, Au, Bi, Cu, In, Ta, Y)
• Solid state nuclear track detectors (235U, 238U,
  natPb)
• Fast neutrons in uranium

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(No Transcript)
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GAMMA-MD

• Lead target graphite moderator
• Deuterons 1.6 GeV
• Activation detectors (Al, Au, Bi, Cu, In, Ta, Y)
• Solid state nuclear track detectors (235U, 238U,
  natPb)
• Fast neutrons in graphite

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Activation detectors

• Monoisotopic materials (Au, Al, Bi, In, Ta, Y, )
• Activation during the irradiation
• (n,xn), (n,g), (n,a) reactions, but also
  (p,pxn),..
• Activity measurement after the irradiation
• Activity a number of produced isotopes

n
HPGe detector
(n,xn), (n,g),
g
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Solid state nuclear track detectors

• Irradiator material (Pb, 235U, 238U) plastic,
  mica
• (n,f) reactions - fission fragments leave tracks
  in plastic
• Chemical etching
• Track counting with microscope
• Tracks a number of fissions

n
chemical etching
n,fission
tracks
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Monte-Carlo simulations

• MCNPX, FLUKA -gt spectral fluence
• Spallation
• Transport of particles
• Spectral fluence folded with cross-sections
  number of produced isotopes or fissions -gt
  experimental values
• Experiment / calculations inside 30
• Cross-sections or
• Monte-Carlo codes ?

by A. Potapenko
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Folding
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Experiment / calculation
Phasotron experiment at 660 MeV
measurement/FLUKA calculation. Detectors are
placed on top of the target along its length.
Energy plus transmutation at 1.5 GeV Measurement
/ MCNPX calculation. Detectors are placed in
radial direction In the first gap.
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Status of cross-sections

• (n,xn) reaction in energy range 10-100 MeV
• Materials in detectors Al, Au, Bi, Cu, In, Ta, Y
• Other 127I, 129I
• Higher x reactions n,3n-n,10n few measurements

• (n,f) reactions in energy range 10-1000 MeV
• Materials Pb, 235U, 238U
• Other heavy materials Au, W, Bi, Th
• For materials other than U few measurements

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Conclusion

• Monte-Carlo predictions of XADS within 30 with
  the experiment better accuracy needed for real
  ADS
• Mostly (n,xn) and (n,f) cross-sections in energy
  range 10-1000 MeV are needed
• Cross-sections that we need can be used also for
  monitoring neutron fluxes at other experiments,
  in reactors ...
• Currently we work on some measurements inside
  EFNUDAT (Ondrej Svoboda talk)