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1 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Nucleon scattering on major actinides using a dispersive optical model with extended couplings R. Capote (IAEA/NDS, Vienna), E. Soukhovitskii (JINER, Minsk), J.M. Quesada (Univ. Sevilla), and S. Chiba (Tokyo IT) 14 th INTERNATIONAL CONFERENCE 14 th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS ON NUCLEAR REACTION MECHANISMS
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2 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Motivation High accuracy requirements were placed on inelastic cross- sections 238 U(n,inl) in the whole energy range up to 20 MeV (OECD/NEA WPEC Subgroup 26, NEA, 2008 ). Changes in PFNS may lead to changes in evaluated inelastic cross sections which are discrepant (cf. INDC(NDS)-0597 (2012)) Physics Data Better nuclear structure should be used in reaction calculations for heavy nuclei (beyond rigid-rotor and vibrational models) Extended multi-band coupling needed with “consistent” coupling (i.e. able to reproduce OM observables for a given CC scheme)
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3 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 R. Lipperheide. Z. Phys. 202, 58 (1967); G. Passatore, Nucl. Phys. A95 (1967) 694 R. Lipperheide and A.K. Schmidt, Nucl. Phys. A112 (1968) 65 C. Mahaux and co-workers : 1984-…; W. Tornow et al (TUNL) A. Molina, R.C., et al, PRC 65 (2002) 034616; R.Charity et al, PRC 76 (07) 044314 SPHERICAL MAGIC NUCLEI, Ca-40, Ca-48, Zr-90, Pb-208,… A.C. Merchant, P.E. Hodgson and H.R. Schelin. Nucl. Sc. Eng. 111 (1992) 132 P. Romain and J.P. Delaroche. Proceedings of the Meeting on Nucleon-Nucleus Optical Model up to 200 MeV, Bruyères-le-Châtel, p.167 (OECD, Paris, 1997) A.B. Smith. Ann. Nucl. Energy 28 (2001); 29 (2002); 31 (2004) DEFORMED NUCLEI (Coupled channels, scattering E>0) Dispersive OMPs E.Soukhovitskii et al, PRC 72 (2005) 024604 ; R.C. et al, PRC 72 (2005) 064610; J.M. Quesada et al, PRC 76 (2007) 057602 ; R.C. et al, JNST 45 (2008) 333–340; R.C. et al, “RIPL …”, Nucl. Data Sheets 110 (2009) 3107–3214; Weili Sun, E.Soukhovitskii, R.C. et al, AIP Conf. Proc. 1235 (2010) 43-49;AIP Conf. Proc.1235 Rui Li et al, PRC 87 (2013) 054611; J.M. Quesada et al, Nucl. Data Sheets 118 (2014) 270–272
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4 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Lane consistent nucleon dispersive OMP Coupled: levels of the ground state band/excited bands Coupling models: Rigid rotor, soft rotor, vibro-rotational model
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5 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Expanded coupling scheme Soft (non-axial) rotor (even-even nuclides) Yu.V.Porodzinkij and E. Soukhovitskii, Phys. At. Nuclei 59 (1996) 228-237 V.M. Maslov et al., J. Nucl. Sc.Tech. Supl.2 (2002) 148-151 CHALLENGE: Derive a dispersive coupled channel potential (Lane consistent) with multiple-band coupling scheme valid for even-even and odd actinides D.W.Chan et al, PRC26 (1982) 841; PRC26 (1982) 861. E.Sheldon. L.E.Beghian, D.W.Chan et al, J.Phys.G:Nucl. Phys. 12, 443 (1986). T. Kawano, N. Fujikawa and Y. Kanda, INDC(JPN)-169 (1993) JENDL-3.2 Vibrational-rotational model (even-even nuclides)
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6 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Nuclear shape parameterization A.Bohr, Mat. Fys. Medd. Dan. Vid. Selsk. 26, No. 14 (1952): Body-fixed frame aligned with principal axes: P.O. Lipas and J.P. Davidson, Nucl. Phys. 26, 80-90 (1961): Octupolar vibrations with even projection better describe low-lying negative parity states => ±2 Rigid rotor + dynamical corrections Small param.
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7 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Optical model potential
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8 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Even-Even Nucleus Selection rules: n ± : vibrational rule Intraband transitions: Quadrupolar-GS: Octupolar-GS:
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9 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Nuclear shape parameterization Intraband transitions: Interband-transitions:
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10 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 ’=-1 ’=-1 isomer Ground state rigid rotor ’=-1 235 U (not coupled bands) K =1/2+ K =5/2+ K =7/2-
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11 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 ’=+1 non-axial ’=-1 axial ’=-1 non-axial 235 U (Coupled bands) K =3/2+K =7/2+ K =3/2- K =7/2- Ground state rigid rotor
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12 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 239 Pu (coupling scheme) GS, K =1/2+ ’=-1 axial ’=-1 ’=+1 non-axial
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13 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 DCC OMP LSQ fit for all “optical“ observables (n,n);(p,p);(p,n) RIPL 2408 OMP: rigid rotor R.C., S.Chiba, E.Sh. Soukhovitskii, J.M. Quesada, E. Bauge, Jnst 45 (2008) 333–340
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14 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 New DCC OMP parameterization
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15 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015
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16 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 Total cross section differences
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17 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015
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18 Roberto Capote, IAEA Nuclear Data Section e-mail: r.capotenoy@iaea.org Web: www-nds.iaea.orgr.capotenoy@iaea.orgwww-nds.iaea.org 14 th Int. Conference on Nuclear Reaction Mechanisms Varenna, Italy, 15-19 June 2015 CONCLUSIONS New DCC OMP with multiple-band coupling derived for nucleon scattering on actinides: 233,235,238 U, 239 Pu, and 232 Th OMP highlights: Based on dispersive relations and Lane consistent. Least-squares fit of a regional set of OMP parameters from (n,n),(p,p) & (p,n) IAS. CC couplings based on rigid rotor with dynamical corrections with derived selection rules for rotational bands built on vibrational (even-even) or single-particle band- heads (odd nuclei). Energy independent geometry. Ground state deformations close to those predicted by Nix and Moller (FRDM)
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