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Cross-sections of Neutron Threshold Reactions studied by activation method

Nuclear Physics Institute, Academy of Sciences of Czech Republic Department of Nuclear Reactors, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague. Cross-sections of Neutron Threshold Reactions studied by activation method. Diploma Thesis

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Cross-sections of Neutron Threshold Reactions studied by activation method

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  1. Nuclear Physics Institute, Academy of Sciences of Czech Republic Department of Nuclear Reactors, Faculty of Nuclear Sciences andPhysical Engineering, Czech Technical University in Prague Cross-sections of Neutron Threshold Reactions studied by activation method Diploma Thesis Vrzalová Jitka Supervisor: RNDr. Vladimír Wagner, CSc.

  2. Outline • - Motivation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • Motivation • Nuclear data libraries • Stochastic and deterministic codes • Neutron sources • Cross-section measurements • Experiments on Cyclotron in Řež • TSL Uppsala experiments • Comparison • Conclusion

  3. Motivation • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • for testing of the programs simulating ADS, it is necessary to determine neutron fields • the neutron fields can be determined using the activation detectors • for neutron detection are used threshold reactions on Au, Al, Bi, In, Ta, Ni, Zn, Y, I • almost no experimental cross-section data for most of observed threshold reactions are available for higher neutron energies (E>20MeV)→it is necessary to perform new cross-section measurements

  4. Evaluated nuclear data libraries x EXFOR • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • nuclear data are summarized in the libraries of nuclear data and gradually updated • data form ENDF-6 • general libraries (BROND-russian, CENDL-chinese, ENDF-american, JEFF- european, JENDL-japanese) • specialized libraries (MENDL, WIND, LA 100, LA 150, NRG-2003) • cross-sections are for the major part of measured isotopes published up to (n,4n) reaction (100 MeV) in ENDF, in EXFOR up to 40 MeV

  5. Stochastic codes • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion MCNP a MCNPX • MCNP simulates transport of neutrons (photons and electrons) in energy range from 10-11 MeV to 20 MeV • MCNPX-connects and improves possibilities of MCNP, which is intended for lower energies and code LAHET, which is advisable for simulation of spallation reaction LAHET • simulates spallation reaction and transport nucleons, pions, muons with energy E≥20 MeV More Monte Carlo-based codes: FLUKA, HETC, NUCLEUS, SHIELD, NMTC, GEM, JAM

  6. Deterministic codes • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion TALYS 1.0 • deterministic code • provides complete calculation of the nuclear reactions in the energy range from 1 keV to 200 MeV • with TALYS code can be obtained the complete overview of cross-sections • the output file contains all usually demanded information, more than 200 keywords could be used in the input file More codes: GNASH, ALICE, STAPRE, EMPIRE, MEND

  7. TALYS 1.0 – nuclear models • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion

  8. TALYS 1.0 – nuclear models Difference between cross-sections models with different nuclear level density and default Fermi model, reaction 209Bi(n,3n)207Bi • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion

  9. Ta Al Au Bi Co In Detection of neutrons • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion

  10. Evaluation • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • decay during cooling, irradiation • unstable irradiation • coincidences • non point-like emitters • detector dead time • detector efficiency • self-absorption

  11. Cross-sectionmeasurements • Requirements for s-measurements by activation method: • high energy neutron source with good intensity • monoenergetic (quasi-monoenergetic) neutrons or well known spectrum • pure monoisotopic samples • good spectroscopic equipment – g and X-rays detectors • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion Then we can calculate Nyield and finally : Number of neutrons in peak Evaluation process: Irradiation→HPGe→Deimos→Corrections→Yield→Cross-section

  12. Neutron sources • source with wide spectrum of neutrons-time of flight method-determination energy of neutrons (system n_TOF in CERN), unsuitable for activation foils • quasi-monoenergetic neutron source - target + accelerator of particles - high-frequency source 7Li(p,n)7Be, 2H(d,n)3He • source CYRIC with energy range from 40 to 90 MeV in „Cyclotron and Radioisotope Center“ in Tohok • new source SPIRAL-2 is under construction in laboratory GANIL in Caen (France) (energy range to 40 MeV, high intensity) • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion

  13. Neutron sources • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion Blue Hall, Uppsala Quasi-monoenergetic neutron source Neutron source on cyclotron U-120M

  14. Experiments in Řež • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • April, May 2009, irradiation of the foils on cyclotron U-120M • quasi-monoenergetic neutron source based on reaction 7Li(p,n)7Be, energy range of this neutron source is 10-37 MeV • proton beam energies 32.5 and 37 MeV • irradiation time about 20 h.,irradiated foils: Ni, Zn, Bi, Cu, In, Al, Au, Ta, Fe and I

  15. Experiments in Řež • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion

  16. Experiments in Uppsala • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • February 2010, June 2008 • quasi-monoenergetic neutron source based on reaction 7Li(p,n)7Be, energy range of this neutron source is 11-175 MeV • proton beam energies 25, 50, 100 MeV (June 2008); 62, 70, 80, and 93 MeV(February 2010) • irradiation time about 8 h.,irradiated foils: Au, Bi, In, Al, Ta, Co, Y and I

  17. Experiments in Uppsala HPGe detector • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion placing samples toward detector samples for irradiation

  18. Comparison Řež, Uppsala Comparison of cross-section reaction (n,2n) 197Au with EXFOR and TALYS • Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion Řež Řež Uppsala Uppsala

  19. Comparison Řež, Uppsala Comparison of cross-section reaction (n,xn) natIn with EXFOR and TALYS • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion Řež Řež Uppsala Uppsala Uppsala

  20. Comparison Řež, Uppsala Comparison of cross-section reaction (n,2n) 64Zn with EXFOR and TALYS • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion Řež Řež Uppsala Uppsala

  21. Conclusion • - Motivation • Introduction • Libraries • Stochastic and • deterministic • codes • Detection of • neutrons • Evaluation • - Cross - section • measurements • - Neutron sources • -Experiments-Řež • - Experiments- • Uppsala • - Comparison • Řež, Uppsala • - Conclusion • Our cross-section measurements in Uppsala and Řež coverwide spectrum of energies • Our results for well known cross-sections agree with other experimental data • We measured also a lot of new experimental data • Near future: publish the measured cross-sections from Uppsala at February 2010 Thanks for attention

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