59-Pr-141 BNL+KAERI EVAL-Oct02 Lee,Chang,Oblozinsky,Mughabghab DIST-mmmyy yyyymmdd ----ENDF/B-VI MATERIAL 5925 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT HISTORY 1980 ENDF/B-VI Evaluation of Schenter, Schmittroth and Prince was done and distributed on 1990. Moldauer potential(Nuc.Phys.47(1963)) was used for total. In capture, above resonance region, general least squares adjustment code FERRET was used. 1999 Feb, ENDF/B-VI MOD 1 Evaluation, S.Y. Oh (KAERI) and S.F. Mughabghab (BNL): Resonance parameters revised. **************************************************************** ENDF/B-VII MOD 1 Evaluation, October 2002, Y.D.Lee(KAERI), J.H.Chang(KAERI), P.Oblozinsky(BNL) and S.F.Mughabghab(BNL) This evaluation is combined result of 2 evaluations produced under the BNL-KAERI project on neutron cross sections for fission products: a) 1999 evaluation in the thermal, resolved resonance and unresolved resonance regions by Oh and Mughabghab. The URR upper energy range is 146.472 keV, given as neutron scattering threshold to the 1-st excited level of 141-Pr (145.44 keV). This evaluation has already been included into ENDF/B-VI MOD 1. b) 2002 evaluation in the fast energy region by Lee and Oblozinsky Merging of these 2 evaluations was performed as follows: - Capture cross sections were adopted from evaluation a) up to the URR upper energy, from evaluation b) at higher energies. - Total cross sections were adopted from evaluation a) up to 146.472keV, from evaluation b) at higher energies, the experimental data were considered. **************************************************************** FAST ENERGY REGION, September 2002, Y.D. Lee(KAERI) and P. Oblozinsky(BNL) This is entirely new evaluation for 141-Pr in the region of 10 keV - 20 MeV. EVALUATION PROCEDURES Adopted procedures are based on careful theoretical analysis utilizing available experimental data, including optical model parameter search and nuclear reaction model calculations [Le02]. OM parameter search was performed in one of two different ways: - Interactive OM search code ABRXPL was used, based on the ABAREX code (spherical OM and Hauser-Feshbach with width fluctuation correction). Nuclear reaction model calculations were performed with the code EMPIRE-II by M. Herman [He01, He02]. This is modularized statistical model code that integrates into a single system a number of important modules and features: - Spherical OM (code SCAT2 by O. Bersillone), and deformed OM including coupled-channels model (code ECIS95 by J. Raynal). - Hauser-Feshbach statistical model including HRTW width fluctuation correction. - Qauntum-mechanical MSD TUL model (codes ORION & TRISTAN by H.Lenske), and MSC NVWY model. - Exciton model (code DEGAS by E. Betak). This code represents good approximation to DSD capture model. - Complete gamma-ray cascade after emission of each particle, including realistic treatment of discrete transitions. - Access to OM segment of the RIPL library [Ri98]. - Built-in input parameter files, such as masses, level density, discrete levels, OM parameters and gamma strength functions. - ENDF-6 formatting (utility code EMPEND by A. Trkov), coupled to grahpical presentation (utility code ZVView by V.Zerkin). PARAMETERIZATION Optical model - SCAT2 code used for spherical OM parameterization. - For neutrons, spherical OM by Lee's was adopted. The resulting total cross section was compared with available EXFOR data (natural) and good agreement was found. - For protons, EMPIRE default OM was used (Becchetti-Greenless). - For alpha particles, EMPIRE default OM was used (McFadden- Satchler). Level densities and discrete levels - Dynamical approach in densities was used, as parametrized by the EMPIRE code, after careful matching to low-lying discrete levels. - Particle-hole level densities for preequilibrium component were set to g=A/15 for neutron channel, and g=A/19 for proton channel. - Discrete levels were taken from the built-in EMPIRE orsi.liv file that is based on the 1996 version of the ENSDF database. Other parameters and tuning - ECIS95 with DWBA default option was used to account for direct contribution to low lying discrete levels in (n,n'). - Preequilibrium components were calculated using the following options: Multistep direct and multistep compound models with default parameters for neutron channel, exciton model using the Kalbach parameter K=100 MeV-3 for (n,gamma) and (n,p) channels. - Default gamma-ray strength function was used for capture. It was adjusted by a factor of 0.2 below 5 MeV, and by a factor of 0.4 at higher energies to reproduce experimental data [Vo86,Za71]. - Fine tuning of parameters was made to reproduce the following cross sections: (n,p) activation measurement [Ka97]. (n,a) activation measurement [Ku64]. (n,2n) activation measurement [Ku97,Mu95]. RESULTS MF=3 Neutron cross sections - EMPIRE calculations were adopted (statistical model, including multistep/preequilibrium decay and direct processes). MT=1 Total - Experimental data[Fo71,Si75] was taken into account to adjust cross sections MT=2 Elastic scattering - Calculated as (total - sum of partial cross sections). MT=4, 51-91 Inelastic scattering - EMPIRE calculations were adopted (statistical model with multistep direct & multistep compound component, and DWBA component for low-lying levels). MT=102 Capture - EMPIRE calculations were adopted (statistical model with exciton preequilibrium component as approximation to direct-semidirect capture with fast neutrons). MT=16 (n,2n) taken from EMPIRE calculations MT=17 (n,3n) taken from EMPIRE calculations MT=22 (n,n'a) taken from EMPIRE calculations MT=28 (n,n'p) taken from EMPIRE calculations MT=103 (n,p) taken from EMPIRE calculations MT=107 (n,a) taken from EMPIRE calculations MF=4 Angular distributions of secondary neutrons - EMPIRE calculations (including SCAT2 results for elastic scattering) were adopted. MF=6 Energy-angle distributions of reaction products - EMPIRE calculations were adopted. --------------------------------------------------------------- REFERENCES [Fo71] D.G.Foster Jr, D.W.Glasgow, "Neutron Total Cross Sections, 2.5 - 15 MeV", J,PR/C,3,576, (1971). [He01] M. Herman "EMPIRE-II Statistical Model Code for Nuclear Reaction Calculations", in Nuclear Reaction Data and Nuclear Reactors, eds. N.Paver, M. Herman and A.Gandini, ICTP Lecture Notes 5 (ICTP Trieste, 2001) pp.137-230. [He02] M.Herman, R.Capote, P.Oblozinsky, A.Trkov and V.Zerkin, "Recent Development and Validation of the Nuclear Reaction Code EMPIRE", in Proc. Inter. Conf. on Nuclear Data for Science and Technology, October 7-12, 2001, Tsukuba, Japan, to be published in J.Nucl.Sci.Tech. (2002). [Ka97] Y.Kasugai, Y.Ikeda, Y.Uno, "Activation Cross Section Measurement for La, Ce, Pr, Nd, Gd, Dy and Er Isotopes by 14 MeV Neutrons", C,97TRIEST,1,635, (1997). [Ku64] P.Kulisic et al., "Nb-93(N,ALPHA) and Pr-141(N,ALPHA) Reactions Differential Cross-Sections, ALPHA-Spectra, Nuclear Temperatures, Level Density Parameters", J,NP,54,17, (1964). [Le02] Yong-Deok Lee, Jonghwa Chang and Pavel Oblozinsky, "Neutron Cross-Section Evaluations of Fission Products in the Fast Energy Region", in Proc. Inter. Conf. on Nuclear Data for Science and Technology, October 7-12, 2001, Tsukuba, Japan, to be published in J.Nucl.Sci.Tech. (2002). [Mu95] S.Murahira et al., "Measurement of Formation Cross Sections Producing Short-Lived Nuclei by 14 MeV Neutrons - Pr, Ba, Ce, Sm, W, Sn, Hf", S,INDC(JPN)-175/U,171, (1995). [Ri98] Handbook for calculations of nuclear reaction data Reference input parameter library, IAEA-TECDOC-1034, 1998. [Si75] R.Singh, H.H.Knitter, "Measurement of Fast Neutron Scattering and Total Cross Sections of 141-Pr", J,ZP/A,272,47, (1975). [Vo86] J.Voignier, S.Joly, G.Grenier, "Capture Cross Sections and Gamma-Ray Spectra from the Interaction of 0.5 to 3.0 MeV Neutron with Nuclei in the Mass Range A=63 to 209", J,NSE,93,43, (1986). [Za71] G.G.Zaikin et al., "Radiative Capture Cross-Sections of Fast Neutrons by Ga-69, Ga-71, La-139 and Pr-141 Isotopes", J,UFZ,16,(7),1205, (1971). **************************************************************** MF=2 has been re-evaluated by S.Y.Oh and S.F.Mughabghab.(May99) RESOLVED RESONANCES in MLBW Calculated 2200 m/s cross sections and resonance integral Cross Section (b) Res. Integral (b)* Capture 11.5 17.6 Elastic 2.70 * Integrated from 0.5 eV to 100 keV with 1/E spectrum Notes: In addition to BNL compilation[Mu81], capture and scattering widths of Taylor[Ta79], J values of Alfimenkov[Al82a], and L values of Morgenstern[Mo69] were incorporated. Two bound level resonances were invoked to reproduce 2200 m/s capture cross section[Mu81] and bound coherent and incoherent scattering lengths in Koester's compilation[Ko91]. Parameters that had not been determined from measurements; radiative width of 86 meV, which was obtained by averaging known 69 widths, was given to remaining resonances, L was assigned by applying Bayesian approach, and J was assigned randomly. Effective scattering radius of 4.93 fm was based on BNL compi- lation[Mu81]. UNRESOLVED RESONANCES in 'all energy-dependent parameters'(LRF=2) Average parameters: S (10**4) (eV)* (meV) s-wave 1.77 118 86 p-wave 0.75 59.0 86 d-wave 0.60 39.3 86 * Level spacing at the neutron separation energy of target+n. Notes: and S0 were deduced from the fitting of reduced widths of resolved resonances to the Porter-Thomas distribution. S1 and S2 were adjusted to reproduce capture cross sections measured by Taylor[Ta79,Al82b], Zaikin[Za71], Konks[Ko64], and Gibbons[Gi61]. Average radiative width of 86 meV was adopted from the resolved resonance region data. Energy- and J-dependence of level spacing were calculated according to the Gilbert-Cameron's level density formula with associated parameters from Mughabghab[Mu98]. REFERENCES [Al82a]Alfimenkov,V.P. et al., Nucl.Phys.,A376,229 (1982) [Al82b]Allen,B.J. et al., Nucl.Sci.Eng.,82,230 (1982) [Gi61] Gibbons,J.H. et al., Phys.Rev.,122,182 (1961) [Ko64] Konks,V.A. et al., Sov.Phys.,19,56 (1964) [Ko91] Koester,L. et al., At. Data Nucl. Data Tables,49,65(1991) [Mo69] Morgenstern,J. et al., Nucl.Phys.,A123,561 (1969) [Mu81] Mughabghab,S.F. et al., Neutron Cross Sections, Vol.1, Part A, Academic Press (1981) [Mu98] Mughabghab,S.F. and Dunford,C.L., Proc.Int.Conf. on Phys. of Nucl.Sci.Technol.,p.784,Long Island,Oct.5-8,1998. [Ta79] Taylor,R.B. et al., Aust.J.Phys.,32,551 (1979) [Za71] Zaikin,G.G. et al., INDC(CCP)-15/U, p.52 (1971) ************************************************************** 1 451 360 0 2 151 343 0 3 1 26 0 3 2 28 0 3 4 19 0 3 16 7 0 3 17 5 0 3 22 12 0 3 28 9 0 3 51 16 0 3 52 12 0 3 53 12 0 3 54 12 0 3 55 12 0 3 56 12 0 3 91 12 0 3 102 19 0 3 103 22 0 3 107 20 0 3 112 14 0 3 600 20 0 3 601 14 0 3 602 13 0 3 603 12 0 3 604 12 0 3 605 12 0 3 649 12 0 3 800 20 0 3 801 20 0 3 802 20 0 3 803 20 0 3 804 20 0 3 805 20 0 3 806 20 0 3 849 20 0 4 2 136 0 4 51 74 0 4 52 84 0 4 53 90 0 4 54 86 0 4 55 82 0 4 56 83 0 4 600 54 0 4 601 52 0 4 602 52 0 4 603 52 0 4 604 52 0 4 605 52 0 4 800 76 0 4 801 76 0 4 802 76 0 4 803 76 0 4 804 76 0 4 805 76 0 4 806 76 0 6 16 902 0 6 17 74 0 6 22 1182 0 6 28 1574 0 6 91 4931 0 6 102 1433 0 6 649 934 0 6 849 1611 0 12 51 3 0 12 52 3 0 12 53 3 0 12 54 3 0 12 55 3 0 12 56 3 0 12 601 3 0 12 602 3 0 12 603 3 0 12 604 3 0 12 605 3 0 12 801 3 0 12 802 3 0 12 803 3 0 12 804 3 0 12 805 3 0 12 806 3 0 14 51 1 0 14 52 1 0 14 53 1 0 14 54 1 0 14 55 1 0 14 56 1 0 14 601 1 0 14 602 1 0 14 603 1 0 14 604 1 0 14 605 1 0 14 801 1 0 14 802 1 0 14 803 1 0 14 804 1 0 14 805 1 0 14 806 1 0