14-Si- 28 JAEA EVAL-AUG07 K.Shibata, S.Kunieda DIST-DEC21 20100127 ----JENDL-5 MATERIAL 1425 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT History 07-08 Evaluated by K.Shibata and S.Kunieda. 10-01 Compiled by K.Shibata. 21-11 revised by O.Iwamoto (MF8/MT4,16,22,28,102,103,107) added 21-11 above 20 MeV, JENDL-4.0/HE merged by O.Iwamoto 21-11 (MF6/MT5) recoil spectrum added by O.Iwamoto MF= 1 General information MT=451 Descriptive data and directory MF= 2 Resonance parameters MT=151 Resolved resonance parameters Resolved resonance region (Reich-Moore formula) : Below 1.75 MeV The resolved resonance parameters were taken from the ENDF/B-VII.0 data, which were evaluated by Leal et al./1/ The following comments were also taken from ENDF/B-VII.0: ------------------------------------------------------------ The following data were included in the analysis: (1) Total cross section data of Perey et al. /2/ for natural silicon, measured on the 47-m flight path at the Oak Ridge Electron Linear Accelerator (ORELA) (2) Transmission data of Harvey et al. /3/ for natural silicon measured on the 200-m flight path at ORELA (3) Total cross section data of Larson et al. /4/, measured on the 80- and 200-m flight paths at ORELA (4) 29Si-oxide /5/ and 30Si-oxide /6/ transmission data of Harvey et al., measured on the 80-m ORELA flight path (5) Elastic scattering thermal cross section for 28Si 1.992+-0.006 barns from Mughabghab /7/. Capture thermal cross section 0.169+-0.004 barns from Raman et al. /8/. Values given by resonance parameters are 1.992 and 0.169 barns respectively. ------------------------------------------------------------ Thermal cross sections and resonance integrals at 300 K ---------------------------------------------------------- 0.0253 eV res. integ. (*) (barns) (barns) ---------------------------------------------------------- Total 2.1612E+00 Elastic 1.9920E+00 n,gamma 1.6915E-01 8.4180E-02 ---------------------------------------------------------- (*) Integrated from 0.5 eV to 10 MeV. MF= 3 Neutron cross sections MT= 1 Total cross section Below 12.5 MeV, the cross sections were taken from the JENDL-3.3 evaluation that was based on experimental data. Above 12.5 MeV, the cross sections were calculated using TNG /9/. MT= 2 Elastic scattering cross section Obtained by subtracting non-elastic cross sections from total cross sections. MT= 4,51-91 (n,n') cross section Calculated with TNG code /9/. For MT=51, the cross sections were replaced by the data measured by Sullivan et al./10/ below 4.15 MeV. As for MT=91, the cross sections, which were calcuated with TNG, were modified between 12 and 14.5 MeV. MT= 16 (n,2n) cross section Calculated with TNG code /9/. MT= 22 (n,na) cross section Calculated with TNG code /9/. MT= 28 (n,np) cross section Taken from JENDL-3.3. MT=102 Capture cross section Calculated with TNG code /9/. MT=103 (n,p) cross section Calculated from MT=600-649. MT=107 (n,a) cross section Calculated from MT=800-849. MT=600-649 partial (n,p) cross section Calculated with TNG code /9/. For MT=600,601, the cross sections were replaced with the data measured by Bateman et al./11/ between 5.513 and 8.973 MeV with a scaling factor of 0.5. MT=800-849 partial (n,a) cross section Calculated with TNG code /9/. For MT=800, the cross sections were replaced with the data measured by Bateman et al./11/ between 5.853 and 7.986 MeV. Finally, the cross section of MT=849 was increased to reproduce the total (n,a) cross section of JENDL-3.3 above 11 MeV. MF= 4 Angular distributions of emitted neutrons MT= 2 Elastic scattering Calculated with TNG code /9/. The shape elastic scattering component was calculated using OPTMAN code./12/ MF= 6 Energy-angle distributions of emitted particles MT= 16 (n,2n) reaction Neutron and gamma-ray spectra calculated with TNG/9/. MT= 22 (n,na) reaction Neutron, alpha-particle, and gamma-ray spectra calculated with TNG/9/. MT= 28 (n,np) reaction Neutron, proton, and gamma-ray spectra calculated with TNG/9/. MT= 51-66 (n,n') reaction Neutron angular distributions and discrete gamma-ray spectra calculated with TNG/9/. MT= 91 (n,n') reaction Neutron spectra, and discrete-continuous gamma-ray spectra calculated with with TNG/9/. MT=102 (n,gamma) reaction Gamma-ray spectra calcualted with TNG/9/. MT=600-614 (n,p) reactions leading to discrete levels Proton angular distributions and discrete gamma-ray spectra calculated with TNG/9/. MT=649 (n,p) reaction leading to continuum levels Proton spectra and discrete-continuous gamma-ray spectra calculated with TNG/9/. MT=800-831 (n,a) reactions leading to discrete levels Alpha-particle angular distributions and gamma-ray spectra calculated with TNG/9/. MT=849 (n,a) reaction leading to continuum levels Alpha-particle spectra and discrete-continuous gamma-ray spectra calculated with TNG/9/. *************************************************************** * Nuclear Model Calculations with TNG Code /9/ * *************************************************************** The description of the model calcualtions is given in Ref.13. < Optical model parameters > Neutrons and protons: Coupled-channel optical model parameters /13/ Alphas: The potential parameters were obtained using the code developed by Kumar and Kailas./14/ < Level scheme of Si- 28 > ------------------------- No. Ex(MeV) J PI ------------------------- 0 0.00000 0 + 1 1.77900 2 + 2 4.61790 4 + 3 4.97990 0 + 4 6.27620 3 + 5 6.69140 0 + 6 6.87880 3 - 7 6.88770 4 + 8 7.38060 2 + 9 7.41630 2 + 10 7.79900 3 + 11 7.93350 2 + 12 8.25870 2 + 13 8.32840 1 + 14 8.41330 4 - 15 8.54360 6 + 16 8.58870 3 + The direct-reaction process was taken into accout for the 1st, 2nd and 15th levels by the coupled-channel method. < Level density parameters > Energy dependent parameters of Mengoni-Nakajima /15/ were used. ---------------------------------------------------------- Nuclei a* Pair Esh T E0 Ematch Econt 1/MeV MeV MeV MeV MeV MeV MeV ---------------------------------------------------------- Si- 29 5.138 2.228 -3.404 1.964 0.625 10.099 7.521 Si- 28 4.489 4.536 -4.401 2.454 1.949 15.409 8.819 Si- 27 4.864 2.309 -2.076 1.916 0.076 10.784 5.262 Al- 28 4.508 0.000 -2.180 2.170 -3.293 10.786 3.012 Al- 27 4.142 2.309 -2.456 2.493 -2.390 16.024 6.948 Mg- 25 4.587 2.400 -0.869 1.901 -0.347 11.340 6.169 Mg- 24 3.964 4.899 -1.374 2.139 2.819 13.649 10.161 ---------------------------------------------------------- References 1) L.C. Leal et al., Proc. Int. Conf. Nuclear Data for Science and Technology, Trieste, 1997, Part I, 929 (1997). 2) F.G. Perey, T.A. Love, W.E. Kinney, Oak Ridge National Laboratory report ORNL-4823 [ENDF-178] (1972). 3) J.A. Harvey, private communication (1996). 4) D.C. Larson, C.H. Johnson, J.A. Harvey, and N.W. Hill, "Measurement of the neutron total cross section of silicon from 5 eV to 730 keV," Oak Ridge National Laboratory report ORNL/TM-5618 (1976) 5) J.A. Harvey, private communication (1996). 6) J.A. Harvey, W.M. Good, R.F. Carlton, et al., Phys.Rev.C 28, 24 (1983). 7) S.F. Mughabghab, M. Divadeenam, N.E. Holden, Neutron Cross Sections, Vol. 1, Part A: Z=1-60, (Academic Press, NY, 1981). 8) S. Raman, et al., Phys.Rev.C 46, 972 (1992). 9) C.Y. Fu, ORNL/TM-7042 (1980); K. Shibata, C.Y. Fu, ORNL/TM- 10093 (1986). 10) N.B. Sullivan et al., Nucl. Sci. Eng., 70, 294 (1979). 11) F.B. Bateman et al., Phys. Rev., 55, 133 (1997). 12) E.Sh. Soukhovitski et al., JAERI-Data/Code 2005-002 (2005). 13) K. Shibata, S. Kunieda, J. Nucl. Sci. Technol., 45, 123 (2008). 14) A. Kumar, S. Kailas, a computer code contained in RIPL-2, Bhabha Atomic Research Center, private communication (2002). 15) A. Mengoni, Y. Nakajima, J. Nucl. Sci. Technol., 31, 151 (1994).