94-Pu-244 JAEA+ EVAL-FEB10 O.Iwamoto, T.Nakagawa, + DIST-MAY10 20100318 ----JENDL-4.0 MATERIAL 9452 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT History 06-12 Fission cross section was revised with GMA code. 07-05 Data were calculated with CCONE code. Data were compiled as JENDL/AC-2008/1/. 10-02 Data of prompt gamma rays due to fission were given. 10-03 Covariance data were given. MF= 1 General information MT=452 Number of Neutrons per fission Sum of MT=455 and 456 MT=455 Delayed neutrons (same as JENDL-3.3) Determined from the systematics of Manero and Konshin/2/. MT=456 Number of prompt neutrons per fission (same as JENDL-3.3) Determined from the data for Pu-240 and Pu242. MF= 2 Resonance parameters MT=151 Resolved resonance parameters (below 290 eV) (almost the same as JENDL-3.3) Recommendation of Mughabghab/3/ was adopted. Mughabghab adopted experimental data of Auchampaugh et al./4/ The average capture width of 20 meV was assumed. Fission widths were determined so as to reproduce integrated measured fission cross sections around each resonance peak. The scattering radius of 9.33 fm adopted was obtained from an optical model calculation. For the present file, a neutron width of a negative resonance was adjusted to the thermal capture cross section of 1.71b, which were determined from the data of Fields et al./5/, Butler et al./6/ and Schuman/7/. Unresolved resonance parameters (290 eV - 100 keV) Unresolved resonance parameters were determined with ASREP code/8/ so as to reproduce the total and capture cross sections calculated with CCONE code/9/, and average fission cross section determined with GMA code/10/. The parameters are used only for self-shielding calculations. Thermal cross sections and resonance integrals (at 300K) ------------------------------------------------------- 0.0253 eV reson. integ.(*) (barns) (barns) ------------------------------------------------------- total 12.099 elastic 10.387 fission 0.0017 3.69 capture 1.710 47.8 ------------------------------------------------------- (*) In the energy range from 0.5 eV to 10 MeV. MF= 3 Neutron cross sections Cross sections above the resolved resonance region except for the elastic scattering (MT=2) and fission cross sections (MT=18, 19, 20, 21, 38) were calculated with CCONE code/9/. MT= 1 Total cross section The cross section was calculated with CC OMP of Soukhovitskii et al./11/. MT= 2 Elastic scattering cross section Calculated as total - non-elastic scattering cross sections. MT=18 Fission cross section The following experimental data were analyzed in the energy range from 290 eV to 20 MeV with the GMA code /10/: Authors Energy range Data points Reference Auchampaugh+ 280 eV - 400 keV 5163 /4/ Behrens+ 102 keV - 19.7 MeV 125 /12/(*1) Moore+ 404 keV - 8.28 MeV 136 /13/ Staples+ 0.514 - 19.5 MeV 124 /14/(*1) *1) ratio to U-235 fission cross section The results of GMA were used to determine the parameters in the CCONE calculation. MT=19, 20, 21, 38 Multi-chance fission cross sections Calculated with CCONE code, and renormalized to the total fission cross section (MT=18). MF= 4 Angular distributions of secondary neutrons MT=2 Elastic scattering Calculated with CCONE code. MT=18 Fission Isotropic distributions in the laboratory system were assumed. MF= 5 Energy distributions of secondary neutrons MT=18 Fission spectra Calculated with CCONE code. MF= 6 Energy-angle distributions Calculated with CCONE code. Distributions from fission (MT=18) are not included. MF=12 Photon production multiplicities MT=18 Fission Calculated from the total energy released by the prompt gamma-rays due to fission which was estimated from its systematics, and the average energy of gamma-rays. MF=14 Photon angular distributions MT=18 Fission Isotoropic distributions were assumed. MF=15 Continuous photon energy spectra MT=18 Fission Experimental data measured by Verbinski et al./15/ for Pu-239 thermal fission were adopted. MF=31 Covariances of average number of neutrons per fission MT=452 Number of neutrons per fission Sum of covariances for MT=455 and MT=456. MT=455 Error of 15% was assumed. MT=456 Covariance was obtained by fitting a linear function to the data at 0.0 and 5.0 MeV with an uncertainty of 5%. MF=32 Covariances of resonance parameters MT=151 Resolved resonance parameterss Format of LCOMP=0 was adopted. Uncertainties of parameters were taken from Mughabghab /16/. For the parameters without any information on uncertainty, the following uncertainties were assumed: Resonance energy 0.1 % Neutron width 10 % Capture width 20 % Fission width 50 % MF=33 Covariances of neutron cross sections Covariances were given to all the cross sections by using KALMAN code/17/ and the covariances of model parameters used in the cross-section calculations. For the fission cross section, covariances obtained with the GMA analysis were adopted. Standard deviation of 90 % was assumed in the energy region below 5 keV. In the resolved resonance region, the following standard deviations were added to the contributions from resonance parameters: Total 20 % Elastic scattering 20 % MF=34 Covariances for Angular Distributions MT=2 Elastic scattering Covariances were given only to P1 components. MF=35 Covariances for Energy Distributions MT=18 Fission spectra Estimated with CCONE and KALMAN codes. ***************************************************************** Calculation with CCONE code ***************************************************************** Models and parameters used in the CCONE/9/ calculation 1) Coupled channel optical model Levels in the rotational band were included. Optical model potential and coupled levels are shown in Table 1. 2) Two-component exciton model/18/ * Global parametrization of Koning-Duijvestijn/19/ was used. * Gamma emission channel/20/ was added to simulate direct and semi-direct capture reaction. 3) Hauser-Feshbach statistical model * Moldauer width fluctuation correction/21/ was included. * Neutron, gamma and fission decay channel were included. * Transmission coefficients of neutrons were taken from coupled channel calculation in Table 1. * The level scheme of the target is shown in Table 2. * Level density formula of constant temperature and Fermi-gas model were used with shell energy correction and collective enhancement factor. Parameters are shown in Table 3. * Fission channel: Double humped fission barriers were assumed. Fission barrier penetrabilities were calculated with Hill-Wheler formula/22/. Fission barrier parameters were shown in Table 4. Transition state model was used and continuum levels are assumed above the saddles. The level density parameters for inner and outer saddles are shown in Tables 5 and 6, respectively. * Gamma-ray strength function of Kopecky et al/23/,/24/ was used. The prameters are shown in Table 7. ------------------------------------------------------------------ Tables ------------------------------------------------------------------ Table 1. Coupled channel calculation -------------------------------------------------- * rigid rotor model was applied * coupled levels = 0,1,2,3,4 (see Table 2) * optical potential parameters /11/ Volume: V_0 = 49.97 MeV lambda_HF = 0.01004 1/MeV C_viso = 15.9 MeV A_v = 12.04 MeV B_v = 81.36 MeV E_a = 385 MeV r_v = 1.2568 fm a_v = 0.633 fm Surface: W_0 = 17.2 MeV B_s = 11.19 MeV C_s = 0.01361 1/MeV C_wiso = 23.5 MeV r_s = 1.1803 fm a_s = 0.601 fm Spin-orbit: V_so = 5.75 MeV lambda_so = 0.005 1/MeV W_so = -3.1 MeV B_so = 160 MeV r_so = 1.1214 fm a_so = 0.59 fm Coulomb: C_coul = 1.3 r_c = 1.2452 fm a_c = 0.545 fm Deformation: beta_2 = 0.24761 beta_4 = 0.03641 beta_6 = -0.02816 * Calculated strength function S0= 0.95e-4 S1= 2.84e-4 R'= 9.31 fm (En=1 keV) -------------------------------------------------- Table 2. Level Scheme of Pu-244 ------------------- No. Ex(MeV) J PI ------------------- 0 0.00000 0 + * 1 0.04420 2 + * 2 0.15500 4 + * 3 0.31790 6 + * 4 0.53500 8 + * 5 0.70800 2 + 6 0.80240 10 + 7 0.95700 3 - ------------------- *) Coupled levels in CC calculation Table 3. Level density parameters -------------------------------------------------------- Nuclide a* Pair Eshell T E0 Ematch 1/MeV MeV MeV MeV MeV MeV -------------------------------------------------------- Pu-245 18.8322 0.7667 2.7988 0.3349 -0.4502 2.4667 Pu-244 18.7661 1.5364 2.7670 0.3408 0.2726 3.2969 Pu-243 18.6999 0.7698 2.4578 0.3280 -0.3352 2.3315 Pu-242 18.6337 1.5428 2.4520 0.3701 0.0291 3.6198 Pu-241 18.5675 0.7730 2.1853 0.3473 -0.4715 2.5167 -------------------------------------------------------- Table 4. Fission barrier parameters ---------------------------------------- Nuclide V_A hw_A V_B hw_B MeV MeV MeV MeV ---------------------------------------- Pu-245 5.600 0.530 5.300 0.520 Pu-244 6.000 1.040 4.700 0.600 Pu-243 5.750 0.680 5.520 0.520 Pu-242 6.150 1.000 4.800 0.600 Pu-241 5.950 0.580 5.480 0.520 ---------------------------------------- Table 5. Level density above inner saddle -------------------------------------------------------- Nuclide a* Pair Eshell T E0 Ematch 1/MeV MeV MeV MeV MeV MeV -------------------------------------------------------- Pu-245 20.7155 0.8944 2.6000 0.3269 -1.5284 2.8944 Pu-244 20.6427 1.7925 2.6000 0.3275 -0.6303 3.7925 Pu-243 20.5699 0.8981 2.6000 0.3633 -2.0616 3.3981 Pu-242 20.4971 1.7999 2.6000 0.3433 -0.8376 3.9999 Pu-241 20.4242 0.9018 2.6000 0.3647 -2.0579 3.4018 -------------------------------------------------------- Table 6. Level density above outer saddle -------------------------------------------------------- Nuclide a* Pair Eshell T E0 Ematch 1/MeV MeV MeV MeV MeV MeV -------------------------------------------------------- Pu-245 20.7155 0.8944 0.6200 0.3609 -0.8159 2.8944 Pu-244 20.6427 1.7925 0.5800 0.3621 0.0827 3.7925 Pu-243 20.9439 0.8981 0.5400 0.3740 -0.9758 3.0981 Pu-242 20.4971 1.7999 0.5000 0.3933 -0.2466 4.1999 Pu-241 20.4242 0.9018 0.4600 0.3804 -0.9744 3.1018 -------------------------------------------------------- Table 7. Gamma-ray strength function for Pu-245 -------------------------------------------------------- K0 = 1.500 E0 = 4.500 (MeV) * E1: ER = 10.90 (MeV) EG = 2.50 (MeV) SIG = 300.00 (mb) ER = 13.80 (MeV) EG = 4.70 (MeV) SIG = 450.00 (mb) * M1: ER = 6.55 (MeV) EG = 4.00 (MeV) SIG = 2.63 (mb) * E2: ER = 10.07 (MeV) EG = 3.17 (MeV) SIG = 6.77 (mb) -------------------------------------------------------- References 1) O.Iwamoto et al.: J. Nucl. Sci. 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