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The n _TOF facility at CERN

The n _TOF facility at CERN. somewhere around h ere. www.cern.ch/ n _TOF. CERN accelerator C omplex. n _TOF. Linac(s): up to 50 MeV PSB: up to 1 GeV PS: up to 24 GeV. www.cern.ch/ n _TOF. The n _TOF facility at CERN. www.cern.ch/ n _TOF. sample. June 2004. n _TOF.

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The n _TOF facility at CERN

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  1. The n_TOF facility at CERN somewhere around here www.cern.ch/n_TOF

  2. CERN accelerator Complex n_TOF Linac(s): up to 50 MeV PSB: up to 1 GeV PS: up to 24 GeV www.cern.ch/n_TOF

  3. The n_TOF facility at CERN www.cern.ch/n_TOF

  4. sample June 2004 n_TOF • n_TOF commissionedin 2002 www.cern.ch/n_TOF

  5. n_TOF basic parameters alberto.mengoni@cern.ch

  6. The real world • n_TOF beam characteristics: Neutron intensity in the full energy range 2nd collimator =1.8 cm

  7. The real world • n_TOF beam characteristics: energy resolution TAC 237Np(n,g) 2004 measurement alberto.mengoni@cern.ch www.cern.ch/n_TOF

  8. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 2002-4 • Cross sections relevant for Nuclear Astrophysics • Measurements of neutron cross sections relevant for Nuclear Waste Transmutation and related Nuclear Technologies • Neutrons as probes for fundamental Nuclear Physics The n_TOF Collaboration

  9. The n_TOF-Ph2 experiments n_TOF-Ph2

  10. The n_TOF-Ph2 experiments n_TOF-Ph2

  11. The second n_TOF beam line & EAR-2 NewExperimentalArea (EAR-2) ~ 20 m n_TOF target EAR-1 (at 185 m) Flight-path length : ~20 m at 90° respect to p-beam direction expected neutron flux enhancement: 20 - 100 drastic reduction of the t0 flash n_TOF-Ph2

  12. problems of sample production and safety issues relaxed EAR-2: Optimized sensitivity consequences for sample mass • 50 mg • 5 mg • 1 mg • 10 mg Improvements (ex: 151Sm case) • sample mass / 3 s/bkgd=1 • use BaF2 TAC e x 10 • use D2O F30 x 5 • use 20 m flight path F30 x 100 boosts sensitivity by a factor of 5000!

  13. The n_TOF Collaboration 40 Research Institutions 120 researchers www.cern.ch/n_TOF

  14. The End www.cern.ch/n_TOF

  15. Results alberto.mengoni@cern.ch

  16. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments U Abbondanno et al. - The n_TOF Collaboration Phys. Rev. Lett. 93 (2004), 161103 152Gd 153Gd 239.47 d 154Gd 155Gd 156Gd 157Gd Gd Eu 151Eu 152Eu 9 h 153Eu 154Eu 8.8 a 155Eu 4.761 a 156Eu 15.2 d 150Sm 151Sm93 a 152Sm 153Sm 42.27 h 154Sm Sm • branching isotope in the Sm-Eu-Gd region: • test for low-mass TP-AGB • branching ratio (capture/b-decay) provides infos on the thermodynamical conditions of the s-processing (if accurate capture rates are known!) The n_TOF Collaboration

  17. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments U Abbondanno et al. - The n_TOF Collaboration NIM A 521 (2004) 454 • 206 mg of 151SmO3 • encapsulated in 0.1 mm Ti • 200 GBq (5.3 Ci) activity PHWT: accuracy better than 2% (MC simulations of WF validated by measurements of resonances in 56Fe & others)

  18. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments U Abbondanno et al. - The n_TOF Collaboration Phys. Rev. Lett. 93 (2004), 161103 Very low background in capture cross section measurements on radioactive targets

  19. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments U Abbondanno et al. - The n_TOF Collaboration Phys. Rev. Lett. 93 (2004), 161103 n_TOF MACS-30 = 3100 ± 160 mb <D0> = 1.48 ± 0.04 eV, S0 = (3.87 ± 0.20)×10-4 Main uncertainty components: - 3% flux normalization - 2% detector’s WF - 3% BG subtraction The n_TOF Collaboration

  20. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm Implications Using the “classical” s-process model we obtain T8 > 4incompatible with realistic He-shell burning conditions 95% of neutrons are produced by 13C(a,n) at kT ~ 8 keV. Under these conditions, 152Gd cannot be produced During the He-burning episode the 22Ne(a,n) is activated at kT ~ 23 keV. The 151Sm b-decay is fast enough to produce 70% of observed 152Gd (solar) • Present main uncertainties: • lb(T) of 151Sm • stellar capture rate Inverse reactions

  21. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments C Domingo-Pardo, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 207Pb(n,g) Very low neutron sensitivity of capture g-ray detection systems & high resolution The n_TOF Collaboration

  22. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments C Domingo-Pardo, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 209Bi(n,g) Very low neutron sensitivity of capture g-ray detection systems & high resolution The n_TOF Collaboration

  23. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments F Gunsing, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 232Th(n,g) Low PS duty-cycle favours meaasurements on radiactive samples The n_TOF Collaboration

  24. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments F Gunsing, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 232Th(n,g) Very low neutron sensitivity of capture g-ray detection systems & high resolution The n_TOF Collaboration

  25. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments Very low neutron sensitivity of capture g-ray detection systems & high resolution The n_TOF Collaboration

  26. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments Very low neutron sensitivity of capture g-ray detection systems & high resolution The n_TOF Collaboration

  27. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments L Marques, et al. - The n_TOF Collaboration The n_TOF Collaboration

  28. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments L Marques, et al. - The n_TOF Collaboration The n_TOF Collaboration

  29. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments L Marques, et al. - The n_TOF Collaboration The extracted resonance parameters were compared with a previous measurement (Boldeman et al., 1976) The n_TOF Collaboration

  30. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments C Moreau, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 ≈20% lower than previous data The extracted resonance parameters were compared with previous measurements (Boldeman et al., 1976; Others) The n_TOF Collaboration

  31. 10 mm Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 93Zr(n,g): raw data from 2004 measurement Very low neutron sensitivity of capture g-ray detection systems & high resolution The n_TOF Collaboration

  32. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments (n,g) x-section of 139La alberto.mengoni@cern.ch

  33. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 139La • Neutron magic N=82 • mostly produced by the s-process • small x-section (resonance dominated) bottleneck in the s-process flow • accurate abbundance measurements exist can be used for normalization of s-process abundance

  34. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 139La(n,g) R Terlizzi, et al. (INFN) The n_TOF Collaboration

  35. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 139La(n,g) R Terlizzi et al. (INFN) Remarkable energy resolution and background conditions have allowed to determine the resonance parameters up to 9 keV In the past, the best experimental data did not exceed 2.7 keV. Up to 2.7 KeV: <capture strength> n_TOF < 10% of Nakajima + Musgrove < 20% of databases MACS-30 in agreement with the FZK activation measurement(s) The n_TOF Collaboration

  36. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 139La(n,g) R Terlizzi et al. (INFN) • The measurement at n_TOF confirmed the MACS-30 of the FZK activation measurement (O’Brien et al., PRC 68 (2003) 35801) • With the new MACS, the s-process contribution to the La production in TP-AGB is 73% (with respect to solar) • A combined analysis with the Eu abundance (mostly r) may furnish evidence on the origin and nature of the s- and r- productions The n_TOF Collaboration

  37. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments • Long b-decay half-life of 187Re • s-only 186Os and 187Os

  38. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments

  39. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments M Mosconi, et al. – (The n_TOF Collaboration) ND2004 Conference, Santa Fe, NM – Sept. 2004 Very low neutron sensitivity of capture g-ray detection systems & high resolution

  40. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments M Mosconi, et al. – (The n_TOF Collaboration) ND2004 Conference, Santa Fe, NM – Sept. 2004 Very low neutron sensitivity of capture g-ray detection systems & high resolution

  41. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm Theory still needed! For example, in 187Os at kT = 30 keV it is: P(gs) = 33% P(1st) = 47% P(all others) = 20%

  42. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 8.5 10.5 Age: Re/Os and Th/U clocks complementary

  43. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 233U(n,g) W Dridi, E Berthoumieux, et al., (Dec. 2004) n_TOF TAC in operation The n_TOF Collaboration

  44. .) Room + target frame background • .) Background due to the Ti canning +1.) 3.) Activity 4.) 234U + 2.) + 3.) Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments 234U(n,g) W Dridi, E Berthoumieux, et al., (Dec. 2004) n_TOF TAC in operation The n_TOF Collaboration

  45. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments D Cano-Ott, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 n_TOF TAC in operation The n_TOF Collaboration

  46. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments D Cano-Ott, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 n_TOF TAC in operation The n_TOF Collaboration

  47. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments D Cano-Ott, et al. - The n_TOF Collaboration ND2004 Conference, Santa Fe, NM – Sept. 2004 1% of statistics n_TOF TAC in operation The n_TOF Collaboration

  48. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments PPACs & FIC-0 (2003) 234U(n,f) An unprecedent wide energy range can be explored at n_TOF in a single experiment The n_TOF Collaboration

  49. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments PPACs & FIC-0 (2003) 234U(n,f) High-resolution data up to high(er) energies The n_TOF Collaboration

  50. Capture 151Sm 204,206,207,208Pb, 209Bi 232Th 24,25,26Mg 90,91,92,94,96Zr, 93Zr 139La 186,187,188Os 233,234U 237Np,240Pu,243Am Fission 233,234,235,236,238U 232Th 209Bi 237Np 241,243Am, 245Cm n_TOF experiments FIC-0 (2003) 235U(n,f) An unprecedent wide energy range can be explored at n_TOF in a single experiment The n_TOF Collaboration

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