11-Na- 23 JAERI EVAL-AUG00 K.SHIBATA (JAERI) DIST-MAY10 20100312 ----JENDL-4.0 MATERIAL 1125 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT HISTORY 2000-8 New evaluation was performed by K.Shibata (JAERI) for JENDL-3.3. 2002-1 Covariances were taken from JENDL-3.2 covariance file. 2010-3 Covariances for MF/MT=3/1,51-58,102 were re-estimated. mf=1 General information mt=451 Descriptive data and dictionary mf=2 Resonance parameters mt=151 Resolved resonance parameters Resolved parameters for MLBW formula were given in the energy region from 1.0e-5 eV to 350 keV. Parameters were mainly taken from the recommended data of BNL /2/, and the data for some levels were modified so that the calculated total cross sec- tions for Na-23 were fitted to the experimental data. The scattering radius was assumed to be 5.2 fermi. Calculated 2200 m/sec cross sections and resonance integrals are as follows: 2200 m/s cross section(b) res. integral(b) elastic 3.024 capture 0.531 0.3122 total 3.555 This part was taken from JENDL-3.2 without any modification. mf=3 Neutron cross sections Below 350 keV, background cross section was given for the total and elastic scattering cross sections. The cross-section data are reproduced from the evaluated resolved resonance parameters with MLBW formula. Above 350 keV, the total and partial cross sections were given pointwise. mt=1 Total In the energies between 350 keV and 14 MeV, evaluated based on the experimental data of Cierjacks/3/ by tracing their fine structures. Above 14 MeV, based on the experimental data of Langsford/4/, Stoler/5/ and Larson/1/. Modefication was done by T.Fukahori(jaeri) to be based on the experimental data of only Larson/1/ above 1 MeV. The total cross section was taken from JENDL-3.2 without any modification. mt=2 Elastic scattering Obtained by subtracting the sum of the partial cross sections from the total cross section. mt=4, 51-78, 91 Inelastic scattering The cross sections were calculated by using the TNG code /6/. The direct cross sections were taken into account for mt=51,52, 53,56. The deformation parameters were estimated by a weak coupling model. For mt=51, the TNG calculations were replaced with the following data: Threshold - 2.15 MeV: Maerten et al./7/ multiplied by 1.25 The factor of 1.25 was derived from a benchmark test made by N. Yamano/8/. 2.15 - 4.0 MeV : JENDL-3.2 mt=51 The neutron optical potential parameters used are: V = 45.82 - 0.2497*Ecm , Vso = 5.5 (MeV) Ws = 7.4162 + 0.0049*Ecm (MeV) r = 1.2572, rs = 1.1393, rso = 1.2687 (fm) a = 0.61646, as = 0.60349, aso = 0.6198 (fm) The level data used in the above calculations were taken from RIPL /9/ as follows: mt level energy(MeV) spin-parity 0.0 3/2+ 51 0.440 5/2+ 52 2.076 7/2+ 53 2.391 1/2+ 54 2.640 1/2- 55 2.704 9/2+ 56 2.982 3/2+ 57 3.678 3/2- 58 3.848 5/2- 59 3.914 5/2+ 60 4.430 1/2+ 61 4.775 7/2+ 62 5.379 5/2+ 63 5.534 11/2+ 64 5.742 5/2+ 65 5.766 3/2+ 66 5.927 7/2+ 67 5.964 3/2- 68 6.042 7/2- 69 6.115 5/2+ 70 6.195 5/2- 71 6.236 9/2+ 72 6.308 1/2+ 73 6.354 9/2- 74 6.578 5/2+ 75 6.618 5/2+ 76 6.735 3/2+ 77 6.820 5/2- 78 6.868 3/2+ Levels above 6.9 MeV were assumed to be overlapping. mt=16, 22, 28, 103, 107 (n,2n),(n,na),(n,np),(n,p),(n,a) Calculated with the TNG code. For mt=103, the TNG calculations were replaced with the JENDL-3.2 data below 11 MeV. mt=102 capture In the energy region from 350 keV to 10 MeV, the cross sections were calculated by TNG. Above 10 MeV, a constant cross section of was assumed. mf=4 Angular distributions of secondary neutrons mt=2 Calculated with the optical model. mt=51-78 Calculated with the TNG code and the DWUCK code/10/. mf=6 Energy-angle distributions of secondary particles mt=16, 22, 28, 91, 103, 107 Calculated with the TNG code. mf=12 Photon production multiplicities mt=4, 16, 22, 28, 51-78,102, 103, 107 Calculated with the TNG code. For mt=102, the measured data /11/ were taken into account between 50 keV and 400 keV. mf=14 Photon angular distributions mt=4, 16, 22, 28, 51-78, 102, 103, 107 Assumed to be isotropic. mf=15 Continuous photon energy spectra mt=4, 16, 22, 28, 102, 103, 107 Calculated with the TNG code. For mt=102, the measured data /11/ were taken into account between 50 keV and 400 keV. mf=33 Covariances of cross sections (ref.12) mt=1 Based on experimental data. A chi-value was 1.887. mt=2 Constructed from mt=1, 16, 22, 28, 51-91, 102, 103, and 107. mt=4 Constructed from mt=51-91. mt=16 Based on experimental data. A chi-value was 1.36. mt=22 The covariances were obtained by using kalman. A chi-value was 2.54. mt=28 The covariances were obtained by using kalman. A chi-value was 2.54. mt=51-91 The covariances were obtained by using kalman. A chi-value was 3.72. mt=102 Based on experimental data. A chi-value was 3.97. mt=103 Based on experimental data. A chi-value was 2.3. mt=107 Based on experimental data. A chi-value was 2.61. ================================================================= For JENDL-4.0, variances for MT=1,51-58,102 were re-estimated by considering the difference between the evaluated and measured data. ================================================================= mf=34 Covariances of angular distributions (ref.12) mt=2 The covariances were obtained by using kalman. A chi-value was 1.01. References 1) Larson D.C. et al. : ORNL/TM-5614 (1976). 2) Mughabghab S.F. et al.:"Neutron Cross Sections", Vol. 1, Part A (1981). 3) Cierjacks S. et al. : KfK-1000 (1969). 4) Langsford A. et al. : 1965 Antwerp Conf. 529 (1965). 5) Stoler P. et al. : 1971 Knoxville Conf. Vol.1, 311 (1971). 6) Shibata K. and Fu C.Y.: ORNL/TM-10093 (1986). 7) Maerten H. et al.: Taken from EXFOR (1994). 8) Yamano N.: Private communication (2001). 9) IAEA: "Handbook for Calculations of Nuclear Reaction Data: Reference Input Parameter Library", IAEA-TECDOC-1034 (1998). 10) Kunz P.D.: Unpublished. 11) Igashira M.: Private communication (2000). 12) Shibata K. et al.: JAERI-Research 97-074 (1997).