1. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 1 Progress Report on Theoretical Tools and Calculations of Cross Sections Relevant to the EAF File Vlad Avrigeanu EURATOM-MEC Fusion Association, “Horia Hulubei” National Institute for Physics & Nuclear Engineering, P.O Box MG-6, 76900 Bucharest, Romania Since EAF-2003 (Prague, June 2002): – Completion (2002/2003) of fast neutron activation calculations for: all stable 58,60,61,62,64 Ni isotopes (+ JRC/IRMM-Geel): [Nucl. Phys. A730, 255 (2004)] all stable 92,94,95,96,97,98,100 Mo isotopes (+ JRC/IRMM, KRI-St.Petersburg) : [ http://tandem.nipne.ro/~vavrig/Publications/2003/papmo_1z.ps] –Analysis (2003/2004) of fast neutron activation of: all stable 180,182,183,184,186 W isotopes (+ UKAEA, TUD-Dresden): [Report EFFDOC-893, NEA/OECD, Paris, May 2004]

2. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 2 BASIC QUESTIONS NUCLEAR-SURFACE EFFECTS ? –in particle-hole level densities: PLD, CPCLibrary, Belfast, 1998] –Phys. Rev. C 58, 295 (1998) –Comp. Phys. Comm. 112, 191 (1998) –in GDH model for pre-equilibrium emission: STAPRE-H95, OECD/NEA-DB, Paris, 1995] –J. Phys. G: Nucl. Phys. 20, 613 (1994) –Phys. Rev. C 65, 014604 (2001) –J. Nucl. Sci. Tech. Suppl. 2, 803 (2002) NUCLEAR MOMENT OF INERTIA ? –in nuclear level densities: [e.g., S.F. Mughabghab, C. Dunford: Phys. Rev. Lett. 82, 4083 (1998)] –J. Nucl. Sci. Tech. Suppl. 2, 746 (2002) –Nucl. Phys. A730, 255 (2004)

3. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 3 Sensitivity of Activation Cross Sections of Tungsten to Nuclear Reaction Mechanisms V. Avrigeanu 1, R. Eichin 2, R.A. Forrest 3, H. Freiesleben 2, M. Herman 4, A.J. Koning 5, and K. Seidel 2 EFF-DOC-893/Rev.1 (June 2004) 1 EURATOM-MEC Fusion Association, “Horia Hulubei” National Institute for Physics & Nuclear Engineering, P.O Box MG-6, 76900 Bucharest, Romania 2 EURATOM-FZK/TUD Fusion Association, Technische Universität Dresden,Dresden, Germany 3 EURATOM-UKAEA Fusion Association, Culham Science Center, United Kingdom 4 Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 5 Nuclear Research and Consultancy Group NRG, P.O. Box 25, 1755 ZG Petten, The Netherlands – EMPIRE-II calculations: g=A/13 MeV -1 (default) A/14 MeV -1 – EMPIRE-II isomeric-state cross sections – (n,n’p+pn+d) reaction cross section discussion Rev.1 (June 2004):

4. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 4 Outline [e.g. 1, EFF-DOC-872, Nov. 2003] Nuclear cross sections calculations -Search for appropriate optical model potentials: n+ 182,183,184,186 W - p+ 181 Ta -Compilation of the available experimental data (E<20 MeV) -Nuclear model calculations (E<20 MeV) -Comparison with all activation experimental data Processing of model calculations results -Cross sections of all individual channels with activation data - [Benchmark experiment analysis updating –calculated-to-experimental (C/E) activity: reduced deviation from unity ] 1 P. Pereslavtsev and U. Fischer, Evaluation of n+ 184 W cross-section data for EFF up to 150 MeV

5. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 5 Flowchart of model calculations EMPIRE-II v.2.18 [ECIS95/SCAT2, DEGAS, MSD-TUL/MSC-H, HF]  t,  R,  CC,  abs - T l (E) neutron deformed optical potential - p-,  - spherical optical potentials - EMPIRE-specific level density, N max < 40 - DEGAS [g=A/13 MeV -1, K=100 MeV 3 ] STAPRE-H v.2002 [SCAT2, GDH, HF] - p-,  - spherical optical potentials - BSFG, E* B n : Junghans/Koning/Chadwick I/I r : 0.5(g.s.)-0.75(B n )-1(15 MeV) - GDH [ g FGM (  ), A K (p,h), f K (p,h,E,F 1 (l,E i )) ] TALYS -0.58 [Koning and Duijvestijn]

6. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 6 Optical model potentials Neutrons (n+ 182,183,184,186 W): SPRT analysis (SPR added in EMPIRE-II output) –P.G. Young+ (1990) [as RIPL-2 in EMPIRE-II] (local) –J.P. Delaroche, as in NEANDC-253”U”, OECD/NEA-DB, 1989 (local) –P.G. Young, NEANDC-222”U”, OECD/NEA-DB, 1986 (global: II.B) –P.G. Young+ (1990) - modified (local) –RIPL-2/P.G. Young+ (1986) - modified (local) Protons (p+ 181 Ta) –R.L. Walter and P.P. Guss, Rad. Effects 92, 1079 (1986) (global) –N. Yamamuro, NDST-1988, Mito, Japan, p.489 (global) –Walter-Guss (1986) - modified (local) Alphas –V. Avrigeanu, P.E. Hodgson, M. Avrigeanu, Phys.Rev.C 49,2137(1994) (global)

7. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 7 Optical model parameters used to describe the scattering of neutrons on W isotopes, and the corresponding absorption cross section for the element W at the incident neutron energy E=14.1 MeV

8. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 8 Comparison of experimental and calculated neutron scattering parameters of 182,184,186 W

9. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 9 Comparison of calculated and experimental neutron total cross sections for 182,183,184,186 W isotopes with emphasis of the lower energy region

10. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 10 Comparison of calculated and experimental neutron total cross sections for 182,183,184,186 W isotopes

11. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 11 Comparison of neutron total cross sections for 182,183,184,186 W isotopes calculated by using presently modified OMPs

12. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 12 Comparison of the calculated and measured proton reaction cross sections and (p,n) reaction cross sections for 181 Ta Walter-Guss (1986) - modified (local): W D =10.48-0.250E+14.94 , E<10 MeV 9.55-0.157E+14.94 , E>10 MeV a D = 0.742-0.0115E, E<20 MeV 0.512, E>20 MeV

13. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 13 Nuclear Level Density Cumulative number of levels against excitation energy for, e.g., 178,179 Hf, and corresponding prediction of the BSFG model

14. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 14 The  -ray strength functions 20 A.V. Ignatyuk, at http://161.5.7.5/RIPL-2/resonances/. 28 D.G. Gardner and F.S. Dietrich, Report UCRL-82998, LLNL-Livermore, 1979. 29 M. Avrigeanu, V. Avrigeanu, G. Cata, and M. Ivascu, Rev. Roum. Phys. 32, 837 (1987). 30 R.L. Macklin, D.M. Drake, and E.D. Arthur, Nucl. Sci. Eng. 89, 98 (1983). Modified energy-dependent Breit-Wigner (EDBW) model 28,29 : f E1 (E  ) Comparison of experimental 20,30 and the calculated average radiative widths -   0 (meV) used for normalization of f E1 (E  ) capture data description

15. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 15 Comparison of calculated and measured neutron capture cross sections of 180,182-184,186 W isotopes

16. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 16 Sample case of isomeric state populated by side- and continuum-decay cascade-feeding [http://tandem.nipne.ro/~vavrig/Publications/2003/papmo_1z.ps]

17. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 17 Comparison of the measured and calculated reaction cross sections for the target nucleus 180 W Calculated values by means of the computer codes EMPIRE-II and TALYS with default global parameters (except the local OMPs) and STAPRE-H with local parameter set given in this work.

18. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 18 Comparison of the measured and calculated reaction cross sections for the target nucleus 182 W Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set. Normalization factor of 1.078 [Vonach+, 1990] is applied to data of Frehaut+ (1980).

19. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 19 Comparison of the measured and calculated reaction cross sections for the target nucleus 183 W Calculated values by means of the computer codes EMPIRE-II and TALYS with default global parameters (except the local OMPs) and STAPRE-H with local parameter set given in this work.

20. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 20 Comparison of the measured and calculated reaction cross sections for the target nucleus 184 W Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set. Normalization factor of 1.078 [Vonach+, 1990] is applied to data of Frehaut+ (1980).

21. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 21 Comparison of the measured and calculated reaction cross sections for the target nucleus 186 W Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set. Normalization factor of 1.078 [Vonach+, 1990] is applied to data of Frehaut+ (1980).

22. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 22 Sensitivity of calculated (n,2n) reaction cross sections vs. reaction mechanisms & model parameters Calculations with EMPIRE-II and default global parameters excepting local OMPs. A normalization factor of 1.078 (Vonach+, 1990) was applied to data of Frehaut+ (1980).

23. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 23 Sensitivity of calculated (n,p) reaction cross sections vs. reaction mechanisms & model parameters Calculations with EMPIRE-II and default global parameters excepting local OMPs.

24. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 24 Sensitivity of calculated (n,p) reaction cross sections vs. reaction mechanism codes Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set.

25. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 25 Sensitivity of calculated reaction cross sections vs. model parameters (s.p.l. g = A/13 - A/15 MeV -1 ) Calculations with EMPIRE-II and default global parameters excepting local OMPs and the s.p.l. value. A normalization factor of 1.078 (Vonach+, 1990) was applied to data of Frehaut+ (1980).

26. V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 26 Conclusions Achievements -Appropriate optical model potentials: n+ 182,183,184,186 W -Unitary description of all activation experimental data (E<20 MeV) by using a local parameter set in STAPRE-H code -Good results of blind calculations and global parameters within EMPIRE-II and TALYS codes -Similar sensitivity of calculations vs. reaction mechanisms & model parameters Problems -Major uncertainty of calculated isomeric cross sections: level schemes & branching ratios -(n,p)-, (n,  )-reaction excitation functions at E n >15 MeV Completion -Similar analysis for: n+ 180,181 Ta, n+ 174,176,177,178,179,180 Hf -Need for - (n,p)-, (n,  )-reaction data at E n >15 MeV (e.g., JRC/IRMM) - (n.d ) reaction data (emission spectra, e.g., LLNL-Livermore)