44-Ru- 99 JNDC EVAL-Mar90 JNDC FP Nuclear Data W.G. DIST-MAY10 20091217 ----JENDL-4.0 MATERIAL 4434 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT HISTORY 90-03 New evaluation for JENDL-3 was completed by JNDC FPND W.G./1/ 93-10 JENDL-3.2 was made by JNDC FPND W.G. 01-04 Res. params were modified for JENDL-3.3. 09-12 Compiled by A.Ichihara. ***** Modified parts for JENDL-3.3 ******************** (2,151) Resolved resonance parameters (J-values) *********************************************************** ***** Modified parts for JENDL-4.0 ******************** (2,151) Unresolved resonance parameters were updated. *********************************************************** MF = 1 General information MT=451 Comments and dictionary MF = 2 Resonance parameters MT=151 Resolved and unresolved resonance parameters Resolved resonance region (MLBW; below 1 keV) The data of JENDL-3.3 was adopted. JENDL-3.3 is the same as JENDL-3.2. ** comments to JENDL-3.3 ** Resonance parameters were evaluated as follows: Resonance energies, neutron and radiation widths were taken from the measurement of Popov et al./2/ As for lowest two levels, the parameters were taken from the compilation of Mughabghab et al./3/ Total spin J for resonances measured by Popov et al. was tentatively estimated with a random number method. Neutron orbital angular momentum l was estimated with a method of Bollinger and Thomas/4/. Average radiation width of 199 meV was deduced and adopted to the levels whose radiation width was unknown. Scattering radius of 6.1 fm was assumed from the systematics of measured values for neighboring nuclides. For JENDL-3.2, total spin J was determined based on the measurements of Coceva et al./5/ and with a randum number method. Unresolved resonance region : 1 keV - 200 keV The neutron strength functions, S0, S1 and S2 were calculated with optical model code CASTHY/6/. The observed level spacing was determined to reproduce the capture cross section calculated with CASTHY. The effective scattering radius was obtained from fitting to the calculated total cross section at 100 keV. The radiation width GG was based on the compilation of Mughabghab et al./3/ Typical values of the parameters at 70 keV: S0 = 0.440E-4, S1 = 4.200E-4, S2 = 0.600E-4, SG = 79.2E-4, GG = 0.195 eV, R = 6.224 fm. The unresolved resonance parameters were calculated using the ASREP code/7/. The parameters should be used only for self-shielding calculation. Thermal cross sections and resonance integrals at 300K (b) ------------------------------------------------------- 0.0253 eV reson. integ.(*) ------------------------------------------------------- total 11.016 elastic 3.705 capture 7.312 171 ------------------------------------------------------- (*) In the energy range from 0.5 eV to 10 MeV. MF = 3 Neutron cross sections Below 1 keV, resolved resonance parameters were given. The spherical optical and statistical model calculation was performed with CASTHY, by taking account of competing reactions, of which cross sections were calculated with PEGASUS/8/ standing on a preequilibrium and multi-step evaporation model. The OMP's for neutron given in Table 1 were determined to reproduce a systematic trend of the total cross section by changing Rso of Iijima-Kawai potential/9/. The OMP's for charged particles are as follows: Proton = Perey/10/ Alpha = Huizenga and Igo/11/ Deuteron = Lohr and Haeberli/12/ Helium-3 and triton = Becchetti and Greenlees/13/ Parameters for the composite level density formula of Gilbert and Cameron/14/ were evaluated by Iijima et al./15/ More extensive determination and modification were made in the present work. Table 2 shows the level density parameters used in the present calculation. Energy dependence of spin cut-off parameter in the energy range below E-joint is due to Gruppelaar /16/. MT = 1 Total Spherical optical model calculation was adopted. MT = 2 Elastic scattering Calculated as (total - sum of partial cross sections). MT = 4, 51 - 91 Inelastic scattering Spherical optical and statistical model calculation was adopted. The level scheme was taken from Ref./17/. No. Energy(MeV) Spin-parity GR. 0.0 5/2 + 1 0.0894 3/2 + 2 0.3221 5/2 + 3 0.3404 7/2 + 4 0.4420 3/2 + 5 0.5755 5/2 + 6 0.6180 7/2 + 7 0.7192 9/2 + 8 1.0480 11/2 + 9 1.0700 11/2 - 10 1.3130 11/2 + 11 1.4960 13/2 + 12 1.5720 15/2 - Levels above 1.7 MeV were assumed to be overlapping. MT = 102 Capture Spherical optical and statistical model calculation with CASTHY was adopted. Direct and semi-direct capture cross sections were estimated according to the procedure of Benzi and Reffo/18/ and normalized to 1 milli-barn at 14 MeV. The gamma-ray strength function (7.80E-03) was determined from the radiation width (0.195+-0.020 eV) and average s-wave resonance level spacing (25+-2 eV/3/). MT = 16 (n,2n) Cross Section MT = 17 (n,3n) Cross Section MT = 22 (n,n'a) Cross Section MT = 28 (n,n'p) Cross Section MT = 32 (n,n'd) Cross Section MT =103 (n,p) Cross Section MT =104 (n,d) Cross Section MT =105 (n,t) Cross Section MT =106 (n,He3) Cross Section MT =107 (n,alpha) Cross Section These reaction cross sections were calculated with the preequilibrium and multi-step evaporation model code PEGASUS. The Kalbach's constant K (= 126.7) was estimated by the formula derived from Kikuchi-Kawai's formalism/19/ and level density parameters. Finally, the (n,p) and (n,alpha) cross sections were normalized to the following values at 14.5 MeV: (n,p) 49.40 mb (systematics of Forrest/20/) (n,alpha) 12.30 mb (systematics of Forrest) MT = 251 Mu-bar Calculated with CASTHY. MF = 4 Angular Distributions of Secondary Neutrons Legendre polynomial coefficients for angular distributions are given in the center-of-mass system for MT=2 and discrete inelas- tic levels, and in the laboratory system for MT=91. They were calculated with CASTHY/6/. MF = 5 Energy Distributions of Secondary Neutrons Energy distributions of secondary neutrons were calculated with PEGASUS for inelastic scattering to overlapping levels and for other neutron emitting reactions. Table 1 Neutron Optical Potential Parameters Depth (MeV) Radius(fm) Diffuseness(fm) ---------------------- ------------ --------------- V = 47.5 R0 = 5.972 a0 = 0.62 Ws = 9.74 Rs = 6.594 as = 0.35 Vso= 7.0 Rso= 5.97 aso= 0.62 The form of surface absorption part is der. Woods-Saxon type. Table 2 Level Density Parameters Nuclide a(1/MeV) T(MeV) C(1/MeV) EX(MeV) Pairing --------------------------------------------------------------- 42-Mo- 95 1.360E+01 7.150E-01 1.847E+00 5.835E+00 1.280E+00 42-Mo- 96 1.403E+01 7.410E-01 6.991E-01 7.645E+00 2.400E+00 42-Mo- 97 1.517E+01 6.800E-01 2.769E+00 6.036E+00 1.280E+00 42-Mo- 98 1.594E+01 6.900E-01 7.358E-01 7.888E+00 2.570E+00 43-Tc- 96 1.741E+01 5.640E-01 1.503E+01 3.650E+00 0.0 43-Tc- 97 1.600E+01 6.700E-01 4.756E+00 6.089E+00 1.120E+00 43-Tc- 98 1.659E+01 6.120E-01 1.776E+01 4.176E+00 0.0 43-Tc- 99 1.600E+01 6.550E-01 2.973E+00 5.984E+00 1.290E+00 44-Ru- 97 1.510E+01 6.390E-01 1.567E+00 5.300E+00 1.280E+00 44-Ru- 98 1.382E+01 7.400E-01 6.070E-01 7.507E+00 2.400E+00 44-Ru- 99 1.650E+01 6.570E-01 4.016E+00 6.235E+00 1.280E+00 44-Ru-100 1.520E+01 7.200E-01 7.835E-01 8.078E+00 2.570E+00 --------------------------------------------------------------- Spin cutoff parameters were calculated as 0.146*SQRT(a)*A**(2/3). In the CASTHY calculation, spin cutoff factors at 0 MeV were assumed to be 12.66 for Ru- 99 and 4.062 for Ru-100. References 1) Kawai, M. et al.: J. Nucl. Sci. Technol., 29, 195 (1992). 2) Ju.P.Popov et al.: Yad. Fiz., 29, 561 (1979). 3) S.F.Mughabghab et al.: "Neutron Cross Sections, Vol. I, Part A", Academic Press (1981). 4) L.M.Bollinger, G.E.Thomas: Phys. Rev., 171,1293(1968). 5) C.Coceva et al.: Nucl. Phys., A 117, 586 (1968). 6) Igarasi, S. and Fukahori, T.: JAERI 1321 (1991). 7) Y.Kikuchi et al., JAERI-Data/Code 99-025 (1999) [in Japanese]. 8) Iijima, S. et al.: JAERI-M 87-025, p. 337 (1987). 9) Iijima, S. and Kawai, M.: J. Nucl. Sci. Technol., 20, 77 (1983). 10) Perey, F.G: Phys. Rev. 131, 745 (1963). 11) Huizenga, J.R. and Igo, G.: Nucl. Phys. 29, 462 (1962). 12) Lohr, J.M. and Haeberli, W.: Nucl. Phys. A232, 381 (1974). 13) Becchetti, F.D., Jr. and Greenlees, G.W.: Polarization Phenomena in Nuclear Reactions ((eds) H.H. Barshall and W. Haeberli), p. 682, The university of Wisconsin Press. (1971). 14) Gilbert, A. and Cameron, A.G.W.: Can. J. Phys., 43, 1446 (1965). 15) Iijima, S., et al.: J. Nucl. Sci. Technol. 21, 10 (1984). 16) Gruppelaar, H.: ECN-13 (1977). 17) Lederer, C.M., et al.: "Table of Isotopes, 7th Ed.", Wiley- Interscience Publication (1978). 18) Benzi, V. and Reffo, G.: CCDN-NW/10 (1969). 19) Kikuchi, K. and Kawai, M.: "Nuclear Matter and Nuclear Reactions", North Holland (1968). 20) Forrest, R.A.: AERE-R 12419 (1986).