12-Mg- 26 DEC,NEDAC EVAL-MAR87 M.HATCHYA(DEC),T.ASAMI(NEDAC) DIST-DEC21 20090828 ----JENDL-5 MATERIAL 1231 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT History 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 =========================================================== The data were taken from JENDL-3.3. =========================================================== HISTORY 87-03 New evaluation was made for JENDL-3. 87-03 Compiled by T.Asami. 01-04 Gamma-ray production data were added. Compiled by K.Shibata. ***** modification for JENDL-3.3 ****************************** (1,451) Updated. (3,251) Deleted. (4,2) Transformation matrix deleted. (5,16-91) INT=22. (12,16-107) Added. (14,16-107) Added. (15,16-107) Added. ***************************************************************** 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 450 keV. Parameters were taken from the recommended data of BNL/1/ and the data for a negative resonance were added so as to reproduce the recommended thermal cross sections for capture and scatter- ing/1/. The scattering radius was assumed to be 4.3 fermi. Calculated 2200 m/sec cross sections and resonance integrals are as follows: 2200 m/s cross section(b) res. integral(b) elastic 2.83 capture 0.038 0.0190 total 2.87 mf=3 Neutron cross sections Below 450 keV, zero background cross section was given and all the cross-section data are reproduced from the evaluated resolv- ed resonance parameters with mlbw formula. Above 450 keV, the total and partial cross sections were given pointwise. mt=1 Total Optical and statistical model calculation was made with the casthy code/2/. The optical potential parameters used are: V = 49.68, Vso = 7.12 (MeV) Ws = 7.76 - 0.5*En, Wv = 0 (MeV) r = 1.17, rs = 1.09, rso = 1.17 (fm) a = 0.6, aso = 0.6, b = 0.69 (fm) mt=2 Elastic scattering Obtained by subtracting the sum of the partial cross sections from the total cross section. mt=4, 51-63, 91 Inelastic scattering Calculated with casthy /2/, taking account of the contribution from the competing processes. The direct component was calculated with the dwuck code/3/. The level data used in the above two calculations were taken from ref./4/ as follows: mt level energy(MeV) spin-parity 0.0 0+ 51 1.8087 2+ 52 2.9384 2+ 53 3.5880 0+ 54 3.9405 3+ 55 4.3180 4+ 56 4.3320 2+ 57 4.3500 3+ 58 4.8340 2+ 59 4.9000 4+ 60 4.9720 0+ 61 5.2910 2+ 62 5.4740 4+ 63 5.6900 1+ Levels above 8.0 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 gnash code/6/ using the above optical model parameters The (n,a) cross sections were normalized to the experimental data of Bormann/5/ at 14 MeV. mt=102 Capture Calculated with the casthy code/2/ and normalized to 1.7 mb at 30 keV. mf=4 Angular distributions of secondary neutrons mt=2 Calculated with the casthy code/2/. mt=51-63 Calculated with the casthy code/2/ and the dwuck code/3/. mt=91 Calculated with the casthy code/2/. mt=16, 22, 28 Isotropic in the laboratory system. mf=5 Energy distributions of secondary neutrons mt=16, 22, 28, 91 Calculated with the gnash code/6/. mf=12 Photon multiplicities and transition probabilities mt=16,22,28,91,103,107 Calculated with gnash. mt=51-63 Stored under option-2 (transition probability array). mt=102 Calculated with casthy. mf=14 Photon angular distributions mt=16,22,28,51-63,91,102,103,107 Isotropic. mf=15 Continuous photon energy spectra mt=16,22,28,91,103,107 Calculated with gnash. mt=102 Calculated with casthy. References 1) Mughabghab S.F. and Garber D.I. :"Neutron cross sections", Vol. 1, Part B (1984). 2) Igarasi S. : J. Nucl. Sci. Tech. 12, 67 (1975). 3) Kunz P.D. : unpublished. 4) ENSDF(Evaluated Nuclear Structure Data File) 5) Bormann M. et al. : 1966 Paris Conf. Vol.1, 225 (1967). 6) Young P.G. and Arthur E.D. : LA-6947 (1977).