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14-Si- 29 TIT,JAERI EVAL-MAR88 H.KITAZAWA,Y.HARIMA,T.FUKAHORI DIST-JAN09 20090105 ----JEFF-311 MATERIAL 1428 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT *************************** JEFF-3.1.1 ************************* ** ** ** Original data taken from: JEFF-3.1 ** ** ** ****************************************************************** ***************************** JEFF-3.1 ************************* ** ** ** Original data taken from: JENDL-3.3 ** ** ** ****************************************************************** HISTORY 88-03 New evaluation was performed for JENDL-3 by Kitazawa, Harima (Tokyo Institute of Tech.) and Fukahori (jaeri). details are given in ref./1/. 88-03 Compiled by Fukahori. 94-01 JENDL-3.2. Compiled by T.Nakagawa (ndc/jaeri) ***** Modified parts for JENDL-3.2 ******************** (3,2) Effects of modification of inelastic scattering cross sections. (3,4), (3,51-79) Cross-section curves were smoothed. (4,16-28), (4,91) Taken from JENDL fusion file (5,16-91) Taken from JENDL fusion file (12,102) Below 2 MeV. *********************************************************** ------------------------------------------------------------- JENDL fusion file /2/ (as of Jan. 1994) Evaluated and compiled by S.Chiba (ndc/jaeri) Cross sections, angular distributions and energy distri- butions were taken from JENDL-3.1. mf=6 of mt=16, 22, 28, and 91 were created by f15tob program/2/ by using Kumabe's systematics/3/. The precompound/compound ratio was taken from the sincros-II calculation/4/. Optical-model, level density and other parameters used in the sincros-II calculation are described in ref./4/. ------------------------------------------------------------- 00-12 JENDL-3.3 Compiled by K.Shibata (jaeri) ***** Modified parts for JENDL-3.3 ********************** (1,451) Updated. (2,151) Upper limit changed to 200 keV. (3,1) Re-calculated. (3,2) Zero background up to 200 keV. (3,102) Modified between 100 and 200 keV. (3,203),(3,207) Calculated. (3,251) Deleted. (4,2) Transformation matrix deleted. (4,16),(4,22) Deleted. (4,28),(4,91) Deleted. (5,16-91) Deleted. (6,16-91) Taken from JENDL fusion file. (6,203),(6,207) Taken from JENDL fusion file. *********************************************************** mf=1 General information mt=451 Descriptive data and dictionary mf=2 Resonance parameters: mt=151 Resolved resonances : 1.0e-5 eV - 0.2 MeV The resonance parameters were searched, using MLBW formula. An initial guess of the parameters was taken from ref./5/. calculated 2200-m/s cross sections and resonance integrals 2200-m/sec res. integ. elastic 2.843 b - capture 0.101 b 0.066 b total 2.944 b - mf=3 Neutron cross sections mt=1 Total cross section Above 0.1 MeV, the cross sections were calculated with the statistical-model code casthy./1,6/ mt=2 Elastic scattering cross sections Obtained by subtracting partial cross sections from the total cross sections. mt=4,51-79,91 Inelastic scattering cross sections Calculated with the statistical-model code casthy /6/ and the coupled-channel model code ecis /7/, taking account of competitive processes for neutron, proton, alpha-particle and gamma-ray emission./1/ Below 11 MeV, the imaginary potential strength of the neutron spherical optical potential was modified from that in ref./1/ to be W = 1.09 + 0.55*E (MeV). Level scheme was taken from ref./8/. no. energy(MeV) spin-parity g.s. 0.0 1/2 + 1. 1.2730 3/2 + 2. 2.0280 5/2 + 3. 2.4250 3/2 + 4. 3.0670 5/2 + 5. 3.6240 7/2 - 6. 4.0800 7/2 + 7. 4.7410 9/2 + 8. 4.8400 1/2 + 9. 4.8950 5/2 + 10. 4.9340 3/2 - 11. 5.2550 9/2 - 12. 5.2860 7/2 + 13. 5.6520 9/2 + 14. 5.8130 7/2 + 15. 5.9490 3/2 + 16. 6.1070 5/2 + 17. 6.1920 7/2 - 18. 6.3780 1/2 - 19. 6.4230 7/2 + 20. 6.4960 1/2 + 21. 6.5220 3/2 + 22. 6.6150 9/2 + 23. 6.6970 3/2 - 24. 6.7100 5/2 + 25. 6.7150 3/2 + 26. 6.7820 11/2 - 27. 6.9070 1/2 - 28. 6.9210 7/2 + 29. 7.0140 5/2 - Continuum levels were assumed above 7.057 MeV. Level density was calculated, using the Gilbert-Cameron formula. The level density parameters were obtained from a cumulative plot of observed levels./1/. For JENDL-3.2, cross sections at threshold energies of the levels were inserted by interpolating the calculated cross sections. mt=16 (n,2n) cross sections Calculated by the statistical model, using the gnash code./1, 9/ Below 11 MeV, the imaginary potential strength of the neutron spherical optical potential was modified from that in ref./1/ to be W = 1.09 + 0.55*E (MeV). mt=22 (n,na) cross sections Calculated by the statistical model, using the gnash code. optical potential for alpha-particles was determined, using the dispersion theory./10/ mt=28 (n,np) cross sections Calculated by the statistical model, using the gnash code. mt=102 capture Calculated with the statistical-model code casthy /6/ and the direct-semidirect-model code hikari /11/. The statistical- model calculations were normalized to 0.6 mb at 0.1 MeV. mt=103 (n,p) cross sections Calculated by the statistical model, using the gnash code. The imaginary potential strength of the proton spherical optical model was modified from that in ref./1/ to be W = 11.0 MeV between 11 and 20 MeV and W = 8.8 + 0.2*E (MeV) below 11 MeV. The strength was determined so as to reproduce observed values /12/. mt=107 (n,a) cross sections Calculated by the statistical model, using the gnash code. Optical potential for alpha-particles was determined, using the dispersion theory./10/ mt=111 (n,2p) cross sections Calculated by the statistical model, using the gnash code. mt=203 Total proton production cross section Sum of mt=28, 103 and 2*(111). mt=207 Total alpha production cross section Sum of mt=22 and 107. mf=4 Angular distributions of secondary neutrons mt=2 Calculated with the statistical-model code casthy /1,6/. mt=51-79 Incoherent sum of the statistical model and coupled-channel model calculations./1/ Calculated with casthy and ecis. mf=6 Energy-angle distributions of secondary particles mt=16,22,28,91,203,207 Taken from JENDL fusion file. mf=12 Gamma-ray multiplicities (below 7.30265 MeV) mt=51-79,102,103,107 Calculated by using the gnash code/1,9/. Multiplicities of mt=102 were determined from energy balance. mf=13 Gamma-ray production cross sections (above 7.30265 MeV) mt=3 Calculated by the statistical model and coupled-channel model, using the gnash code /9/ and the ecis /7/ code. Branching ratios for transitions between discrete levels were taken from ref./8/. Gamma-ray transition strength in the continuum was calculated by the Brink-Axel giant resonance model for e1 transition and by the Weisskopf single-particle model for e2 and m1 transition./1/ mf=14 Gamma-ray angular distributions mt=3,51-79,102,103,107 Isotropic distribution was assumed. mf=15 Gamma-ray spectra mt=3,102,103,107 Calculated with the gnash code./1,9/ References 1) Kitazawa H. et al.: Proc. Int. Conf. Nuclear Data for Science and Technology, Mito, 1988, p.473, (1988). 2) Chiba S. et al.: JAERI-M 92-027, p.35 (1992). 3) Kumabe I. et al.: Nucl. Sci. Eng., 104, 280 (1990). 4) Yamamuro N.: JAERI-M 90-006 (1990). 5) Mughabghab S.F. et al.: "Neutron Cross Sections, Vol. 1 Part A", Academic Press (1981). 6) Igarasi S. and Fukahori T.: JAERI 1321 (1991). 7) Raynal J.: Computer program ecis79 for coupled-channel calculations, 1979 (unpublished). 8) Endt P.M. and Van der Leun C.: Nucl. Phys., A310, 1 (1978). 9) Young P.G. and Arthur E.D.: LA-6947 (1977). 10) Kitazawa H. et al.: Unpublished. 11) Kitazawa H.: Computer program hikari for direct-semidirect capture calculations, 1980 (unpublished). 12) Ikeda Y. et al.: JAERI 1312 (1988).Back |