73-Ta-181

 73-Ta-181 NAIG       EVAL-MAR87 N.YAMAMURO                       
                      DIST-MAY10                       20100120   
----JENDL-4.0         MATERIAL 7328                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
HISTORY                                                           
76-03 The evaluation for JENDL-1 /1/ was made by H.Yamakoshi      
      (ship research institute) and JENDL-1 compilation group.    
83-03 JENDL-1 data were adopted for JENDL-2 and extended to 20    
      mev. mf=5 was revised, and unresolved resonance parameters  
      were added by Y.Kikuchi (jaeri) /2/.                        
83-11 Comment data were added.                                    
87-03 The evaluation for JENDL-3 was made by N.Yamamuro (naig).   
      Resonance parameters were added by new experimental data.   
      Neutron cross sections, except total and elastic scattering 
      cross sections, and energy distributions of secondary       
      neutrons and photons were calculated with gnash /3/ and     
      casthy /4/ codes.                                           
94-02 JENDL-3.2.                                                  
      Compiled by T.Nakagawa (ndc/jaeri)                          
                                                                  
     *****   Modified parts for JENDL-3.2   ********************  
      (12,102)                                                    
             Data were determined from energy balance.            
     ***********************************************************  
02-02 JENDL-3.3                                                   
      Compiled by K.Shibata (jaeri)                               
                                                                  
      *****  Modified parts for JENDL-3.3   ********************  
      (1,451)        Updated                                      
      (3,1),(3,2)    Re-calculated                                
      (3,107)        Revised below 500 keV                        
      (3,251)        Deleted                                      
      (4,2)          Transformation matrix deleted.               
      (5,16-91)      Distributions at threshold were changed.     
      **********************************************************  
10-01 JENDL-4.0                                                   
      Compiled by K.Shibata(jaea)                                 
                                                                  
      ****  Modified parts for JENDL-4.0   *********************  
      (1,451)        Updated                                      
      (2,151)        Unresolved resonance parameters revised      
      (3,1)          Re-calculated                                
      (3,2),(3,102)  Data beween 2.4 keV and 100 keV given        
      **********************************************************  
                                                                  
                                                                  
mf=1   General information                                        
  mt=451     Descriptive data and dictionary                      
                                                                  
mf=2   Resonance parameters                                       
  mt=151     Resolved and unresolved resonance parameters         
  Resolved parameters for MLBW formula                            
                                                                  
      The energy region from 1.0e-5eV to 2.4 keV. Parameters were 
      taken from refs./5,6,7/ for positive resonances, and from   
      ENDF/B-IV for a negative resonance. The radiative width of  
      0.059ev was assumed for the resonance whose radiative width 
      was unknown.                                                
                                                                  
  Unresolved parameters                                           
                                                                  
      In the energy range from 2.4 to 100keV, parameters were     
      determined to reproduce the measured capture cross sections 
      /6,8/. The parameters are as follows,                       
                                                                  
         R= 7.8 fm , Dobs= 4.2 eV , radiative width= 0.065 eV,    
         So= 1.7e-04  S1= 2.0e-05  S2= 2.3e-04  nl= 3             
                                                                  
      ************************************************************
      For JENDL-4.0, the unresolved resonance parameters were     
      revised.  The parameters should be used only for self-      
      shielding calculations.                                     
      ************************************************************
                                                                  
      calculated 2200-m/sec cross sections and resonance integrals
                        2200-m/sec      res. integ                
          elastic         5.65 b            -                     
          capture        20.67 b         660.43 b                 
          total          26.32 b            -                     
                                                                  
mf=3   Neutron cross sections                                     
  mt=1   Total                                                    
    Evaluated from experimental data.                             
    **************************************************************
    In JENDL-4.0, the data beween 2.4 and 100 keV were taken      
    from the pointwise file of JENDL-3.3.                         
    **************************************************************
  mt=2   Elastic scattering                                       
    (total cross section) - (reaction cross section)              
  mt=4,51-64,91 Inelastic scattering                              
     Below 3 MeV,calculated with optical and statistical model    
     code casthy/4/, and above 3 MeV calculated with statistical  
     and preequilibrium model code gnash/3/.  Wilmore-Hodgson's   
     optical-model potential parameters/9/ were used, which       
     reproduced the experimental nonelastic cross sections up to  
     15 MeV.                                                      
                                                                  
          V=47.01-0.267E-0.00118E**2(MeV)                         
          Ws=9.52-0.053E            (MeV)                         
          ro=1.268,   as=0.66       (fm)                          
          rs=1.241,   as=0.48       (fm)                          
                                                                  
     The level scheme was adopted from ref./10/.                  
                                                                  
               no.        energy (MeV)      spin-parity           
               g.s.         0.0                7/2+               
                1           0.0062             9/2-               
                2           0.136              9/2+               
                3           0.159             11/2-               
                4           0.301             11/2+               
                5           0.338             13/2-               
                6           0.482              5/2+               
                7           0.495             13/2+               
                8           0.543             15/2-               
                9           0.615              1/2+               
               10           0.619              3/2+               
               11           0.717             15/2+               
               12           0.773             17/2-               
               13           0.965             17/2+               
               14           1.028             19/2-               
                                                                  
     Levels above 1.03MeV were assumed to overlapping.            
     Level density parameters used were as follows,               
                                                                  
             1/MeV      pair-E     T(MeV)    E (MeV)   spin-cutoff
    Ta-178    22.5       0.0        0.54      4.2         13.0    
    Ta-179    22.0       0.4        0.53      4.2         18.0    
    Ta-180    22.5       0.0        0.54      4.2         13.0    
    Ta-181    22.0       0.73       0.52      4.3         29.0    
    Ta-182    21.8       0.0        0.56      4.3         13.0    
                                                                  
  mt=16   (n,2n) cross section                                    
    Calculated with gnash/3/.                                     
  mt=17   (n,3n) cross section                                    
    Calculated with gnash/3/.                                     
  mt=28   (n,n p) cross section                                   
    Calculated with gnash /3/.                                    
  mt=102  Radiative capture cross section                         
    Calculated with casthy/4/.                                    
    **************************************************************
    In JENDL-4.0, the data beween 2.4 and 100 keV were taken      
    from the pointwise file of JENDL-3.3.                         
    **************************************************************
  mt=103   (n.p) cross section                                    
    Calculated with gnash/3/.                                     
                                                                  
mf=4   Angular distributions of secondary neutrons                
  mt=2   Calculated with casthy/4/.                               
  mt=16,17,28                                                     
    Isotropic in the laboratory system was assumed.               
  mt=51-64,91                                                     
    Calculated with casthy/4/.                                    
                                                                  
mf=5   Energy distributions of secondary neutrons                 
  mt=16,17,28,91                                                  
    Calculated with gnash/3/.                                     
                                                                  
mf=12   Photon production multiplicities (option1)                
  mt=51-64.91,16,17,28,103                                        
    Calculated with gnash/3/.                                     
  mt=102                                                          
    Rrom energy balance.                                          
                                                                  
mf=14   Photon angular distributions                              
    Isotropic in the center-of-mass system was assumed.           
                                                                  
mf=15   Continuous photon energy spectra                          
  mt=91,16,17,28,102,103                                          
    Calculated with gnash/3/.                                     
                                                                  
References                                                        
 1) Igarasi,S. et al.: JAERI 1261 (1979)                          
 2) (Ed.) Nakagawa,T.: JAERI-M 84-103 (1984)                      
 3) Young,P.G. and Arthur,E.D.: "GNASH, A Preequilibrium          
    Statistical Nuclear-Model Code for Calculation of Cross       
    Sections and Emission Spectra", LA-6974 (1977).               
 4) Igarasi,S. and Fukahori,T.: JAERI 1321 (1991).                
 5) Mughabghab,S.F, and Garder,D.I.: BNL325, 3rd ed. (1973).      
 6) Macklin,R,L,: Nucl,Sci,Eng., 86,362 (1984).                   
 7) Tsubone,I., Nakajima,Y. and Kanda,Y.: Private communication   
 8) Yamamuro,N., Saito,K., Emoto,T., Wada,t., Fujita,Y. and       
    Kobayashi,K.: J.Nucl.Sci.Technol., 17, 582 (1980).            
 9) Wilmore,D. and Hodgson,P.E.: Nucl, Phys., 55, 673 (1964).     
10) Firestone,R.B.: Nucl, Data Sheets 43, 289 (1984).