94-Pu-236

 94-Pu-236 JAERI      EVAL-FEB02 O.Iwamoto                        
                      DIST-MAR02 REV3-FEB02            20020226   
----JENDL-3.3         MATERIAL 9428                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
HISTORY                                                           
79-04 New evaluation was made by T.Hojuyama (MAPI) /1/ in the     
      energy range from 1.0E-5 eV to 20 MeV.                      
89-07 Cross sections below 9.15 eV were modified by Y.Kikuchi and 
      T.Nakagawa (JAERI).                                         
94-06 JENDL-3.2.                                                  
       nu-p, nu-d and nu-total were modified.                     
      Compiled by T.Nakagawa (NDC/JAERI)                          
01-12 JENDL-3.3                                                   
       Resonance parameter, Cross section, angular distribution   
       and energy distribution were modified by O.Iwamoto         
       (NDC/JAERI)                                                
     *****   Modified parts for JENDL-3.3   ********************  
      (2,*), (3,*), (4,*), (5,*)                                  
     ***********************************************************  
                                                                  
                                                                  
MF=1 General Information                                          
  MT=451 Comment and dictionary                                   
  MT=452, 455, 456                                                
       Data were not modified from JENDL-3.2.                     
                                                                  
MF=2 Resonance Parameters                                         
  MT=151 Resolved and unresolved resonance parameters             
    1) Resolved resonance : 1.0E-5 to 10 eV                       
       Multilevel Breit-Wigner type resonance parameters          
       were taken from ENDF-B/VI                                  
    2) Unesolved resonance : 1 eV to 30 keV                       
       Parameters were obtained to reproduce evaluated total,     
       fission and capture cross sections. The fission cross      
       section were evaluated based on measured data/2/.          
       Other cross sections were estimated from statistical model 
       calculation and multiplied by the ratio of calculated to   
       the experimental fission cross section.                    
    3) Thermal Cross Sections and Resonance Integrals             
       Calculated 2200-m/s cross sections and resonance integrals.
                            2200 m/sec    Res. Integ.             
               total        331.1   b        -                    
               elastic       16.34  b        -                    
               fission      169.4   b       58.8 b                
               capture      145.4   b       401  b                
                                                                  
MF=3 Neutron Cross Sections                                       
  MT=1 Total cross section                                        
       Obtained by CC optical model calculation. Optical potential
       parameters were taken from Sukhovitskii's evaluation/3/.   
       The deformation parameters were taken from Moller's        
       calculation/4/.                                            
  MT=2 Elastic scattering cross section                           
       Obtained by subtracting the other cross sections from total
       cross section.                                             
  MT=4,51-54,91 Inelastic scattering cross sections               
       Obtained by optical and statistical model calculations.    
       Level scheme was taken from Ref./5/                        
                   No.   En(keV) Spin-Parity                      
                   g.s.    0.0      0 +                           
                    1     44.63     2 +                           
                    2    147.45     4 +                           
                    3    305.80     6 +                           
                    4    515.7      8 +                           
                Continuum levels assumed above 640 keV.           
  MT=16,17 (n,2n) and (n,3n) cross sections                       
       Obtained by statistical model calculations.                
  MT=18,19,20,21 Fission cross sections                           
       Obtained by statistical model calculations.                
       Fission barrier parameters were adjusted to reproduce      
       experimental fission cross section/2/.                     
  MT=102 Capture cross section                                    
       Obtained by statistical model calculations.                
                                                                  
MF=4 Angular Distribution of Secondary Neutrons                   
  MT=2,51-54                                                      
       Based on optical and statistical model calculation.        
  MT=16,17,18-21                                                  
       Isotropic in the laboratory system.                        
  MT=91                                                           
       Statistical plus excition model calculation with Kalbach's 
       systematics/6/.                                            
                                                                  
MF=5 Energy Distribution of Secondary Neutrons                    
  MT=16,17,91                                                     
       Based on statistical model calculation.                    
  MT=18,19,20,21                                                  
       Fission spectrum of Maxwellian form adopted. Temperatures  
       were estimated by Howerton's systematics/7/.               
                                                                  
References                                                        
 1) T. Hojuyama:  Proc. '79 Fall Meet. of A.E.S.J.,Tokai (1979)   
    C43.                                                          
 2) E.A. Gromova et al.: Sov. J. At. Energ., 68, 223 (1990)       
 3) E.Sh. Sukhovistskii et al.: J. Nucl. Sci. Tech. 37, 120 (2000)
 4) P. Moller et al.: Atomic Data and Nucl. Data Tables 59, 185   
    (2000)                                                        
 5) M.R. Schmorak: Nucl. Data Sheets, 63, 139 (1991)              
 6) C. Kalbach: Phys. Rev. C37, 2350 (1988)                       
 7) R.J. Howerton, R.J. Doyas: Nucl. Sci. Eng. 46, 414 (1971)     
                                                                  
------------------------------------------------------------------
               JENDL-3.2 comment                                  
------------------------------------------------------------------
 94-Pu-236 MAPI,JAERI Eval-Apr79 T.Hojuyama, Y.Kikuchi, T.Nakagawa
                      Dist-Sep89 Rev2-Jun94                       
History                                                           
79-04 New evaluation was made by T.Hojuyama (MAPI) /1/ in the     
      energy range from 1.0E-5 eV to 20 MeV.                      
89-07 Cross sections below 9.15 eV were modified by Y.Kikuchi and 
      T.Nakagawa (JAERI).                                         
94-06 JENDL-3.2.                                                  
       nu-p, nu-d and nu-total were modified.                     
      Compiled by T.Nakagawa (NDC/JAERI)                          
                                                                  
     *****   Modified parts for JENDL-3.2   ********************  
      (1,452), (1,455), (1,456)                                   
     ***********************************************************  
                                                                  
                                                                  
MF=1 General Information                                          
  MT=451 Comment and dictionary                                   
  MT=452 Number of neutrons per fission                           
       Sum of Nu-p nad Nu-d.                                      
  MT=455 Delayed neutrons per fission                             
       Average values of systematics by Tuttle/2/, Benedetti et   
       al./3/ and Waldo et al./4/  Decay constants were assumed   
       to be the same as those of Pu-238 evaluated by Brady and   
       England/5/.                                                
  MT=456 Prompt neutrons per fission                              
       Based on systematics by Manero and Konshin/6/, and by      
       Howerton/7/.                                               
                                                                  
MF=2 Resonance Parameters                                         
  MT=151 Resolved resonance parameters : 1.0E-5 to 9.15 eV        
       Average capture width, S0,  and R were estimated from   
       systematics/8,9/.  The first positive resonance was located
       at 6.3 eV, and its neutron width was estimated from S0.    
       The fission width was determined so that the fission cross 
       section calculated from unresolved resonance formula with  
       the fission width might smoothly connect at 10 keV to the  
       cross section in high energy region.  A negative resonance 
       was added at -0.8 eV and the parameters were adjusted so as
       to reproduce the fission cross section of 170 b at 0.0253  
       eV/10/ and reasonable capture cross section.               
                                                                  
                 : 0.030 eV                                   
               R     : 9.46 fm                                    
                  : 6.3  eV                                    
               S0    : 1.25E-4 /8,9/                              
                                                                  
       Calculated 2200-m/s cross sections and resonance integrals.
                            2200 m/sec    Res. Integ.             
               total        331.1   b        -                    
               elastic       16.34  b        -                    
               fission      169.4   b       58.8 b                
               capture      145.4   b       401  b                
                                                                  
MF=3 Neutron Cross Sections                                       
  MT=  1 Total cross section                                      
       Obtained by optical model calculation.  Optical potential  
       parameters were taken from Murata's evaluation /11/ except 
       real potential.                                            
             ---Optical Potential Parameters---                   
               V  = 39.5-0.05*En         (MeV)                    
               Ws =  6.5+0.15*En         (MeV)                    
               Vso=  7.0                 (MeV)                    
               r0 = rso= 1.32 ,rs = 1.38 (fm)                     
               a  = aso= 0.47 ,b  = 0.47 (fm)                     
  MT=  2 Elastic scattering cross section                         
       Obtained by optical and statistical model calculations.    
  MT=4,51-54,91 Inelastic scattering cross sections               
       Obtained by optical and statistical model calculations.    
       Level scheme was taken from Ref./12/ except 4th level of   
       which energy was based on Lynn /13/.                       
                   No.   En(keV) Spin-Parity                      
                   g.s.    0.0      0 +                           
                    1     44.6      2 +                           
                    2    145        4 +                           
                    3    305        6 +                           
                    4    523        8 +                           
                Continuum levels assumed above 661 keV.           
  MT=16,17 (n,2n) and (n,3n) cross sections                       
       Calculated with statistical model based on Pearlstein /14/.
  MT=18,19,20,21 Fission cross sections                           
       Below 10 keV:                                              
        Calculated from the unresolved resonance formula with the 
        following parameters.                                     
           S0 = 1.25E-4, S1 = 2.22E-4,  = 6.3 eV,              
           = 0.0415 eV.   = 0.00355 eV.                   
       Above 10 keV:                                              
        Calculated from fission plateau cross sections /11,15/ and
        Hill-Wheeler type barrier penetration factor /16/.        
        Fission barrier parameters were taken from Weigmann /17/. 
  MT=102 Capture cross section                                    
       Calculated by optical and statistical model with  of   
       41.5 milli-eV and  of 6.3 eV.                           
  MT=251 Mu-bar                                                   
       Calculated with optical model.                             
                                                                  
MF=4 Angular Distribution of Secondary Neutrons                   
  MT=  2         Based on optical and statistical model calcula-  
                 tion.                                            
  MT=51-54       Isotropic in the center-of-mass system.          
  MT=16-21,91    Isotropic in the laboratory system.              
                                                                  
MF=5 Energy Distribution of Secondary Neutrons                    
  MT=16,17,91    Evaporation spectrum assumed                     
  MT=18,19,20,21 Fission spectrum of Maxwellian form adopted.     
                 Theta taken from evaluation of Terrell/18/.      
                                                                  
References                                                        
 1) Hojuyama T.:  Proc. '79 Fall Meet. of A.E.S.J.,Tokai (1979)   
    C43.                                                          
 2) Tuttle R.J.: INDC(NDS)-107/G+special, p.29 (1979),            
 3) Benedetti G. et al.: Nucl. Sci. Eng., 80, 379 (1982).         
 4) Waldo R. et al.: Phys. Rev., C23, 1113 (1981).                
 5) Brady M.C. and England T.R.: Nucl. Sci. Eng., 103, 129 (1989).
 6) Manero F. and Konshin V.A.:  At. Energy Rev.,10, 637 (1972).  
 7) Howerton R.J.: Nucl. Sci. Eng.,62, 438 (1977).                
 8) Mughabghab S.F. and Garber D.I.:  BNL 325,3rd Ed.,1,(1973).   
    Mughabghab S.F.: "Neutron Cross Sections, Vol. 1, Part B",    
    Academic Press (1984).                                        
 9) Musgrove A.R.de L.: AAEC/E 277 (1973).                        
10) Gindler J.E. et al.: Phys. Rev.,115, 1271 (1959).             
11) Matsunobu H. et al.: Proc. Int. Conf. on Nuclear Cross        
    Sections for Technology, Knoxville (1979) 715.                
12) Schmorak M.R.: Nucl. Data Sheets,20, 165 (1977).              
13) Lynn J.E.: The Theory of Neutron Resonance Reactions(1968),   
    Oxford University Press.                                      
14) Pearlstein S.: Nucl. Sci. Eng.,23, 238 (1965).                
15) Behrens J.W.: Phys. Rev. Lett.,39,(1977) 68                   
16) Hill D.L. and Wheeler J.A.: Phys. Rev.,89, 1102 (1953).       
17) Weigmann H. and Theobald J.P.: Nucl  Phys.,A187,(1972) 305    
18) Terrell J.: Proc. IAEA Symposium on Physics and Chemistry of  
    Fission , Salzburg (1965)