14-Si- 30

 14-SI- 30 TIT,JAERI  EVAL-MAR88 H.KITAZAWA,Y.HARIMA,T.FUKAHORI   
                      DIST-MAR02 REV3-JUL01            20010713   
----JENDL-3.3         MATERIAL 1431                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
HISTORY                                                           
88-03  New evaluation was performed for JENDL-3 by Kitazawa,      
       Harima (Tokyo Institute of Tech.) and Fukahori (jaeri).    
       Details are given in ref./1/.                              
88-03  Compiled by fukahori.                                      
94-01  JENDL-3.2.                                                 
       Compiled by T.Nakagawa (ndc/jaeri)                         
                                                                  
     *****   Modified parts for JENDL-3.2   ********************  
      (3,2)                Effects of modification of inelastic   
                           scattering cross sections.             
      (3,4), (3,51-69)     Cross-section curves were smoothed.    
      (4,16-28), (4,91)    Taken from JENDL fusion file           
      (5,16-91)            Taken from JENDL fusion file           
      (12,102)             Below 2 mev.                           
     ***********************************************************  
                                                                  
     -------------------------------------------------------------
      JENDL fusion file /2/  (as of Jan. 1994)                    
          Evaluated and compiled by S.Chiba (ndc/jaeri)           
                                                                  
          Cross sections, angular distributions and energy distri-
       butions were taken from JENDL-3.1.  mf=6 of mt=16, 22, 28, 
       and 91 were created by f15tob program/2/ by using Kumabe's 
       systematics/3/.  The precompound/compound ratio was taken  
       from the sincros-II calculation/4/.                        
          Optical-model, level density and other parameters used  
       in the sincros-II calculation are described in ref./4/.    
     -------------------------------------------------------------
00-12  JENDL-3.3                                                  
       Compiled by K.Shibata (jaeri)                              
       *****  Modified parts for JENDL-3.3  **********************
       (1,451)                Updated.                            
       (3,203),(3,207)        Calculated.                         
       (3,251)                Deleted.                            
       (4,2)                  Transformation matrix deleted.      
       (4,16),(4,22)          Deleted.                            
       (4,28),(4,91)          Deleted.                            
       (5,16-91)              Deleted.                            
       (6,16-91)              Taken from JENDL fusion file.       
       (6,203),(6,207)        Taken from JENDL fusion file.       
       ***********************************************************
                                                                  
                                                                  
mf=1  General information                                         
 mt=451   Descriptive data and dictionary                         
                                                                  
mf=2  Resonance parameters:                                       
 mt=151                                                           
   Resolved resonances  : 1.0e-5 eV - 0.5 MeV                     
   The resonance parameters were searched, using MLBW formula.    
   An initial guess of the parameters was taken from ref./5/.     
                                                                  
    calculated 2200-m/s cross sections and resonance integrals    
                  2200-m/sec    res. integ.                       
      elastic       2.491 b          -                            
      capture       0.108 b       0.709 b                         
      total         2.598 b          -                            
                                                                  
mf=3  Neutron cross  sections                                     
 mt=1      Total cross section                                    
   Above 0.5 MeV, the cross sections were calculated with the     
   statistical-model code casthy./1,6/                            
                                                                  
 mt=2      Elastic scattering cross sections                      
   Obtained by subtracting partial cross sections from the total  
   cross sections.                                                
                                                                  
 mt=4,51-69,91  Inelastic scattering cross sections               
   Calculated with the statistical-model code casthy /6/ and the  
   coupled-channel model code ecis /7/, taking account of         
   competitive processes for neutron, proton, alpha-particle and  
   gamma-ray emission./1/ Below 11 MeV, the imaginary potential   
   strength of the neutron spherical optical potential was        
   modified from that in ref./1/ to be W = 1.09 + 0.55*E (MeV).   
                                                                  
   Level scheme was taken from ref./8/.                           
          no. energy(MeV)  spin-parity                            
         g.s.    0.0          0 +                                 
           1.    2.2355       2 +                                 
           2.    3.4982       2 +                                 
           3.    3.7696       1 +                                 
           4.    3.7877       0 +                                 
           5.    4.8090       2 +                                 
           6.    4.8305       3 +                                 
           7.    5.2300       3 +                                 
           8.    5.2790       4 +                                 
           9.    5.3720       0 +                                 
          10.    5.4876       3 -                                 
          11.    5.6130       2 +                                 
          12.    5.9500       4 +                                 
          13.    6.5030       4 -                                 
          14.    6.5370       2 +                                 
          15.    6.6340       2 -                                 
          16.    6.6400       0 +                                 
          17.    6.7447       1 -                                 
          18.    6.8650       2 -                                 
          19.    6.9140       2 +                                 
                                                                  
   Continuum levels were assumed above 6.999 MeV.  Level density  
   was calculated, using the Gilbert-Cameron formula.  The level  
   density parameters were obtained from a cumulative plot of     
   observed levels./1/.                                           
                                                                  
   For JENDL-3.2, cross sections at threshold energies of the     
   levels were inserted by interpolating the calculated cross     
   sections.                                                      
                                                                  
 mt=16   (n,2n) cross sections                                    
   Calculated by the statistical model, using the gnash code./1,  
   9/ below 11 MeV, the imaginary potential strength of the       
   neutron spherical optical potential was modified from that in  
   ref./1/ to be W = 1.09 + 0.55*E (MeV).                         
                                                                  
 mt=22   (n,na) cross sections                                    
   Calculated by the statistical model, using the gnash code.     
   optical potential for alpha-particles was determined, using    
   the dispersion theory./10/                                     
                                                                  
 mt=28   (n,np) cross sections                                    
   Calculated by the statistical model, using the gnash code.     
                                                                  
 mt=102  capture                                                  
   Calculated with the statistical-model code casthy /6/ and the  
   direct-semidirect-model code hikari /11/.  The statistical-    
   model calculations were normalized to 0.6 mb at 0.5 MeV.       
                                                                  
 mt=103  (n,p) cross sections                                     
   Calculated by the statistical model, using the gnash code.  The
   imaginary potential strength of the proton spherical optical   
   model was modified from that in ref./1/ to be W = 11.0 MeV     
   between 11 and 20 MeV and W = 8.8 + 0.2*E (MeV) below 11 MeV.  
                                                                  
 mt=107  (n,a) cross sections                                     
   Calculated by the statistical model, using the gnash code.     
   Optical potential for alpha-particles was determined, using    
   the dispersion theory./10/                                     
                                                                  
 mt=111  (n,2p) cross sections                                    
   Calculated by the statistical model, using the gnash code.     
                                                                  
 mt=203  Total proton production cross section                    
   Sum of mt=28, 103 and 2*(111).                                 
                                                                  
 mt=207  Total alpha production cross section                     
   Sum of mt=22 and 107.                                          
                                                                  
                                                                  
mf=4    Angular distributions of secondary neutrons               
 mt=2                                                             
   Calculated with the statistical-model code casthy /1,6/.       
 mt=51-69                                                         
   Incoherent sum of the statistical model and coupled-channel    
   model calculations./1/  Calculated with casthy and ecis.       
                                                                  
mf=6    Energy-angle distributions of secondary particles         
 mt=16,22,28,91,203,207                                           
   Taken from JENDL fusion file.                                  
                                                                  
mf=12   Gamma-ray multiplicities (below 7.23453 MeV)              
 mt=51-69,102,107                                                 
   Calculated by using the gnash code/1,9/.  Multiplicities of    
   mt=102 were determined from energy balance.                    
                                                                  
mf=13   Gamma-ray production cross sections (above 7.23453 MeV)   
 mt=3                                                             
   Calculated by the statistical model and coupled-channel model, 
   using the gnash code /9/ and the ecis /7/ code.  Branching     
   ratios for transitions between discrete levels were taken from 
   ref./8/.  Gamma-ray transition strength in the continuum was   
   calculated by the Brink-Axel giant resonance model for e1      
   transition and by the weisskopf single-particle model for e2   
   and m1 transition./1/                                          
                                                                  
mf=14   Gamma-ray angular distributions                           
 mt=3,51-69,102,107                                               
   Isotropic distribution was assumed.                            
                                                                  
mf=15   Gamma-ray spectra                                         
 mt=3,102,107                                                     
   Calculated with the gnash code./1,9/                           
                                                                  
References                                                        
 1) Kitazawa H. et al.: Proc. Int. Conf. Nuclear Data for Science 
    and Technology, Mito, 1988, p.473, (1988).                    
 2) Chiba S. et al.: JAERI-M 92-027, p.35 (1992).                 
 3) Kumabe I. et al.: Nucl. Sci. Eng., 104, 280 (1990).           
 4) Yamamuro N.: JAERI-M 90-006 (1990).                           
 5) Mughabghab S.F. et al.: "Neutron Cross Sections, Vol. 1 Part  
    A", Academic Press (1981).                                    
 6) Igarasi S. and Fukahori T.: JAERI 1321 (1991).                
 7) Raynal J.: Computer program ecis79 for coupled-channel        
    calculations, 1979 (unpublished).                             
 8) Endt P.M. and Van der Leun C.: Nucl. Phys., A310, 1 (1978).   
 9) Young P.G. and Arthur E.D.: LA-6947 (1977).                   
10) Kitazawa H. et al.: unpublished.                              
11) Kitazawa H.: Computer program hikari for direct-semidirect    
    capture calculations, 1980 (unpublished).