1 / 24

A nton ín Krása, Mitja Majerle for the Energy plus Transmutation collaboration

Neutron Production in Spallation Reactions of p+Pb, d+Pb at GeV Energies (Experiment versus Monte Carlo simula tion ). A nton ín Krása, Mitja Majerle for the Energy plus Transmutation collaboration. Outline. Motivation Performed experiments Energy + Transmutation setup

wilma-herrera
Download Presentation

A nton ín Krása, Mitja Majerle for the Energy plus Transmutation collaboration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Neutron Production in Spallation Reactions of p+Pb, d+Pb at GeV Energies(Experiment versus Monte Carlo simulation) Antonín Krása, Mitja Majerlefor the Energy plus Transmutation collaboration

  2. Outline • Motivation • Performed experiments • Energy + Transmutation setup • Monte-Carlo simulations • Neutron spectra • Low-energy region (activation foils) • Intermediate region (activation foils) • High-energy region (SSNTD) • Sources of differences experiment × simulations

  3. Motivation and Tasks • Experimental data for testing the codes for simulation of neutron production and transport in ADT systems • Measurement of neutron field produced in irradiation of: • thick target, • thick target + moderator, • thick target + fissionable blanket + moderator • with relativistic protons and deuterons • Comparison: experimental× Monte-Carlo simulations  check accuracy of nuclear models and x-section libraries

  4. Experiments onthick target (+ moderator) .

  5. Phasotron setup 660 MeV Synchrophasotron setup 885 MeV

  6. Experimentson Energy+Transmutation setup

  7. ENERGY + TRANSMUTATION setup • target: Pb (28.66 kg) • blanket: U (206.4 kg) • shielding: Cd + (CH2)n

  8. Measurement of activated foils • High Purity Germanium -spectrometer

  9. Spatial distributions of yields in Al- and Au-foils • Example of yields at 1.5 GeV proton irradiation of E+T setup

  10. Monte-Carlo simulations • MCNPX 2.6.C • FLUKA Description of U/Pb assemblyin MCNPX

  11. Produced neutron spectrum • Spallation produces neutrons with keV-GeV energies • (n,g)-reaction covers neutrons with energies up to MeV

  12. MCNPX simulation of activation reaction yields

  13. Compilation of total neutron yields for p,d+Pb

  14. SSNTD Activation detectors

  15. Detectors • Activation detectors : • 197Au(n,xn)197-x+1Au • Bi, Al, Co, Ta, In • Gamma spectrometry • Solid State Nuclear Track Detectors : • natPb, natU, 235U + mica foils where fission fragments leave their tracks • Optical microscopy

  16. Results – Phasotron experiment660 MeV, bare, lead target Experiment Experiment/simulation

  17. Energy Plus Transmutation • Au detectors • Longitudinal • Radial in the first gap • SSNTD • Radial in all gaps

  18. Results – EPT, 1 GeV protons

  19. Results – EPT, 1.5 GeV protons

  20. Discrepancies • Disagreement • 1.5 GeV • 2 GeV bigger • 2.52 GeV deuterons – zero ?! • Only in radial direction • Only for threshold detectors, SSNTD are ok • Causes : • Experimental error • Simulations

  21. Experimental error ? • Systematic uncertainties were studied carefully with sets of MCNPX simulations, they are limited to ca. 30% (foil displacement, beam determination) • Transport of activated material out of foil is below 5% • Spectrometry – 5% • … ?

  22. Simulation errors ? • Spallation : • INC (E>160 MeV), • pre-equilibrium (160MeV>E>40MeV), • evaporation(40 MeV>E). • Transport of HE neutrons in uranium blanket • More tests: • Analysis of Yurevich experiments (angular spallation neutron distribution, Ep>1.5 GeV) • EPT experiment without blanket at 1.5 GeV or 2 GeV • Repeat 1 experiment (1.5 GeV or 2 GeV)

  23. Results – EPT, 1.5 GeV protonsFLUKA code - preliminary

More Related