35-Br- 81 JAEA EVAL-AUG09 K.Shibata, A.Ichihara, S.Kunieda DIST-MAY10 20091118 ----JENDL-4.0 MATERIAL 3531 -----INCIDENT NEUTRON DATA ------ENDF-6 FORMAT History 09-08 Evaluated by K. Shibata, JAEA. 09-10 Compiled by K. Shibata. MF= 1 General information MT=451 Descriptive data and directory MF= 2 Resonance parameters MT=151 Resolved and unresolved resonance parameters Resolved resonance region (mlbw formula) : below 13 keV resonance energies for the 304 levels and for the remaining 3 levels were based on the measurements by Macklin/1/ and by Ohkubo et al./2/, respectively. Neutron and radiation widths were determined by different methods according to the following three conditions, respectively. 1) In cases where total width and neutron capture area measured by macklin were given for a resonance level, the neutron and radiation widths were simultaneously obtained by solving a quadratic equation. 2) In cases where neutron capture area measured by macklin and g*(reduced neutron width) measured by Ohkubo et al. were available, the radiation widths were derived from the both data. 3) In cases where only neutron capture area by Macklin was available, or g*(neutron width) by Ohkubo et al. was smaller than neutron capture area by Macklin for a resonance level, the average radiation width of 279 meV given by Macklin was adopted. The neutron width was derived from this average radiation width and the neutron capture area. In addition, if the value of g*(averaged radiation width) was smaller than neutron capture area for some resonance levels, the average radiation width was increased depending on the value of neutron capture area, so as to satisfy the following condition: g*(average radiation width) > neutron capture area. Total spin J of some resonances was tentatively estimated with a random number method. Neutron orbital angular momentum L was assumed to be 0 for all resonance levels. Scattering radius was taken from the graph (fig. 1, Part A) given by Mughabghab et al./3/ A negative resonance was added so as to reproduce the thermal capture cross section given by Mughabghab et al. In JENDL-4, the radiation width of a negative resonance was changed to 123 meV. Unresolved resonance region: 13 keV - 700 keV The parameters were obtained by fitting to the total and capture cross sections calculated from POD /4/. The unresolved parameters should be used only for self-shielding calculation. Thermal cross sections and resonance integrals at 300 K ---------------------------------------------------------- 0.0253 eV res. integ. (*) (barns) (barns) ---------------------------------------------------------- Total 5.9956E+00 Elastic 3.6394E+00 n,gamma 2.3561E+00 4.6622E+01 ---------------------------------------------------------- (*) Integrated from 0.5 eV to 10 MeV. MF= 3 Neutron cross sections MT= 1 Total cross section Calculated with POD code /4/. MT= 2 Elastic scattering cross section Obtained by subtracting non-elastic cross sections from total cross sections. MT= 3 Non-elastic cross section Sum of partial non-elastic cross sections. MT= 4,51-91 (n,n') cross section Calculated with POD code /4/. MT= 16 (n,2n) cross section Calculated with POD code /4/. MT= 17 (n,3n) cross section Calculated with POD code /4/. MT= 22 (n,na) cross section Calculated with POD code /4/. MT= 28 (n,np) cross section Calculated with POD code /4/. MT= 32 (n,nd) cross section Calculated with POD code /4/. MT=102 Capture cross section Calculated with POD code /4/. MT=103 (n,p) cross section Calculated with POD code /4/. MT=104 (n,d) cross section Calculated with POD code /4/. MT=105 (n,t) cross section Calculated with POD code /4/. MT=106 (n,He3) cross section Calculated with POD code /4/. MT=107 (n,a) cross section Calculated with POD code /4/. MT=203 (n,xp) cross section Calculated with POD code /4/. MT=204 (n,xd) cross section Calculated with POD code /4/. MT=205 (n,xt) cross section Calculated with POD code /4/. MT=206 (n,xHe3) cross section Calculated with POD code /4/. MT=207 (n,xa) cross section Calculated with POD code /4/. MF= 4 Angular distributions of emitted neutrons MT= 2 Elastic scattering Calculated with POD code /4/. MF= 6 Energy-angle distributions of emitted particles MT= 16 (n,2n) reaction Neutron spectra calculated with POD/4/. MT= 17 (n,3n) reaction Neutron spectra calculated with POD/4/. MT= 22 (n,na) reaction Neutron spectra calculated with POD/4/. MT= 28 (n,np) reaction Neutron spectra calculated with POD/4/. MT= 32 (n,nd) reaction Neutron spectra calculated with POD/4/. MT= 51 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 52 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 53 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 54 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 55 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 56 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 57 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 58 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 59 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 60 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 61 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 62 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 63 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 64 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 65 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 66 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 67 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 68 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 69 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 70 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 71 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 72 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 73 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 74 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 75 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 76 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 77 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 78 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 79 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 80 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 81 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 82 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 83 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 84 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 85 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 86 (n,n') reaction Neutron angular distributions calculated with POD/4/. MT= 91 (n,n') reaction Neutron spectra calculated with POD/4/. MT= 203 (n,xp) reaction Proton spectra calculated with POD/4/. MT= 204 (n,xd) reaction Deuteron spectra calculated with POD/4/. MT= 205 (n,xt) reaction Triton spectra calculated with POD/4/. MT= 206 (n,xHe3) reaction He3 spectra calculated with POD/4/. MT= 207 (n,xa) reaction Alpha spectra calculated with POD/4/. MF=12 Gamma-ray multiplicities MT= 3 Non-elastic gamma emission Calculated with POD code /4/. MF=14 Gamma-ray angular distributions MT= 3 Non-elastic gamma emission Assumed to be isotropic. MF=15 Gamma-ray spectra MT= 3 Non-elastic gamma emission Calculated with POD code /4/.*************************************************************** * Nuclear Model Calculations with POD Code /4/ * *************************************************************** 1. Theoretical models The POD code is based on the spherical optical model, the distorted-wave Born approximaiton (DWBA), one-component exciton preequilibrium model, and the Hauser-Feshbach-Moldauer statis- tical model. With the preequilibrim model, semi-empirical pickup and knockout process can be taken into account for composite-particle emission. The gamma-ray emission from the compound nucleus can be calculated within the framework of the exciton model. The code is capable of reading in particle transmission coefficients calculated by separate spherical or coupled-channel optical model code. 2. Optical model parameters Neutrons: Coupled-channel optical model parameters /5/ Protons: Koning and Delaroche /6/ Deuterons: Lohr and Haeberli /7/ Tritons: Becchetti and Greenlees /8/ He-3: Becchetti and Greenlees /8/ Alphas: Lemos /9/ potentials modified by Arthur and Young /10/ 3. Level scheme of Br- 81 ------------------------- No. Ex(MeV) J PI ------------------------- 0 0.00000 3/2 - 1 0.27599 5/2 - 2 0.53620 9/2 + 3 0.53820 3/2 - 4 0.56603 3/2 - 5 0.64990 3/2 - 6 0.76715 5/2 - 7 0.78940 5/2 + 8 0.82829 3/2 - 9 0.83677 7/2 - 10 0.90600 5/2 - 11 0.97500 3/2 - 12 1.02370 5/2 - 13 1.07600 1/2 - 14 1.10530 1/2 - 15 1.17000 1/2 - 16 1.17680 13/2 + 17 1.18990 7/2 - 18 1.23788 3/2 + 19 1.26600 7/2 - 20 1.26640 9/2 - 21 1.30000 5/2 - 22 1.32300 5/2 - 23 1.32740 3/2 + 24 1.34980 5/2 + 25 1.37150 7/2 + 26 1.40100 3/2 - 27 1.48180 7/2 - 28 1.51290 3/2 - 29 1.52230 11/2 + 30 1.53590 3/2 - 31 1.53600 3/2 + 32 1.54160 9/2 + 33 1.54300 5/2 + 34 1.54320 3/2 - 35 1.58700 3/2 - 36 1.58740 1/2 + ------------------------- Levels above 1.59740 MeV are assumed to be continuous. 4. Level density parameters Energy-dependent parameters of Mengoni-Nakajima /11/ were used ---------------------------------------------------------- Nuclei a* Pair Esh T E0 Ematch Elv_max 1/MeV MeV MeV MeV MeV MeV MeV ---------------------------------------------------------- Br- 82 10.599 0.000 2.092 0.832 -2.117 6.154 1.261 Br- 81 10.293 1.333 2.879 0.880 -1.411 8.480 1.587 Br- 80 10.191 0.000 3.385 0.903 -3.155 7.747 0.771 Br- 79 10.079 1.350 3.698 0.897 -1.795 9.044 1.513 Se- 81 10.589 1.333 1.999 0.755 -0.063 6.204 2.253 Se- 80 10.645 2.683 2.442 0.815 0.539 8.768 3.226 Se- 79 10.473 1.350 3.245 0.875 -1.656 8.768 0.729 As- 79 10.079 1.350 2.572 0.864 -0.976 7.886 1.518 As- 78 10.399 0.000 2.885 0.736 -1.468 4.841 0.536 As- 77 9.864 1.368 3.386 0.907 -1.622 8.902 1.676 ---------------------------------------------------------- 5. Gamma-ray strength functions M1, E2: Standard Lorentzian (SLO) E1 : Generalized Lorentzian (GLO) /12/ 6. Preequilibrium process Preequilibrium is on for n, p, d, t, He-3, and alpha. Preequilibrium capture is on. References 1) Macklin, R.L.: Nucl. Sci. Eng., 99, 133 (1988). 2) Ohkubo, M. et al.: J. Nucl. Sci. Technol. 18, 745 (1981). 3) Mughabghab, S.F. et al.: "Neutron Cross Sections, Vol. I, Part A", Academic Press (1981). 4) A.Ichihara et al., JAEA-Data/Code 2007-012 (2007). 5) S.Kunieda et al., J. Nucl. Sci. Technol. 44, 838 (2007). 6) A.J.Koning, J.P.Delaroche, Nucl. Phys. A713, 231 (2003). 7) J.M.Lohr, W.Haeberli, Nucl. Phys. A232, 381 (1974). 8) F.D.Becchetti,Jr., G.W.Greenlees, "Polarization Phenomena in Nuclear Reactions," p.682, The University of Wisconsin Press (1971). 9) O.F.Lemos, Orsay Report, Series A, No.136 (1972). 10) E.D.Arthur, P.G.Young, LA-8626-MS (1980). 11) A.Mengoni, Y.Nakajima, J. Nucl. Sci. Technol. 31, 151 (1994). 12) J.Kopecky, M.Uhl, Nucl. Sci. Eng. 41, 1941 (1990).