12-Mg- 24

                      DIST-MAY10                       20090828   
----JENDL-4.0         MATERIAL 1225                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
 87-03  New evaluation was made for JENDL-3.                      
 87-03  Compiled by T.Asami.                                      
 93-04  JENDL-3.2                                                 
        Compiled by T.Nakagawa (ndc/jaeri)                        
     *****   modified parts for JENDL-3.2   ********************  
      (4,91)               Changed to the laboratory system       
 01-04  Gamma-ray production data were added.                     
        Compiled by K.Shibata.                                    
*****  modification for JENDL-3.3  ****************************** 
(1,451)            Updated.                                       
(3,1)              Revised.                                       
(3,2)              Re-calculated.                                 
(3,251)            Deleted.                                       
(4,2)              Transformation matrix deleted.                 
(5,16-91)          INT=22.                                        
(12,16-107)        Added.                                         
(14,16-107)        Added.                                         
(15,16-107)        Added.                                         
 09-08  MF/MT=12/58 was corrected.                                
        Compiled by K.Shibata (jaea)                              
mf=1  General information                                         
 mt=451  Descriptive data and dictionary                          
mf=2  Resonance parameters                                        
 mt=151  Resolved resonance parameters                            
   Resolved parameters for MLBW formula were given in the energy  
   region from 1.0e-5 eV to 520 keV.  Parameters were taken from  
   the recommended data of BNL/1/ and the data for a negative     
   resonance were added so as to reproduce the recommended thermal
   cross sections for capture and scattering/1/.  The data for    
   some levels were modified so that the calculated total cross   
   sections of the element Mg were fitted to the experimental data
   of Hibdon/2/ and Singh/3/.  The scattering radius was assumed  
   to be 5.4 fermi.  Calculated 2200 m/sec cross sections and     
   resonance integrals are as follows:                            
           2200 m/s cross section(b)     res. integral(b)         
   elastic      3.75                                              
   capture      0.050                       0.0312                
   total        3.80                                              
mf=3  Neutron cross sections                                      
  Below 520 keV, no background cross section is given and all the 
  cross-section data are reproduced from the evaluated resolved   
  resonance parameters with the MLBW formula.                     
  Above 520 keV, the total and partial cross sections are given in
  the pointwise form.                                             
  ***** For JENDL-3.3 ********************************************
  Negative background cross sections were considered for mt=1,2 to
  reproduce the elemental total cross sections of JENDL-3.2       
 mt=1 Total                                                       
  Optical and statistical model calculation was made with         
  casthy code/4/. The optical potential parameters used are:      
       V = 49.68,                Vso = 7.12   (MeV)               
      Ws = 7.76 - 0.5*En,         Wv = 0      (MeV)               
       r = 1.17,  rs = 1.09,  rso = 1.17      (fm)                
       a = 0.6,   aso = 0.6,   b = 0.69       (fm)                
  ***** For JENDL-3.3 ********************************************
  The elemental data of JENDL-3.2 were taken after subtracting    
  Mg-25,26 contributions.                                         
 mt=2 Elastic scattering                                          
  Obtained by subtracting the sum of the partial cross sections   
  from the total cross section.                                   
 mt=4, 51-61, 91 Inelastic scattering                             
  Calculated with casthy /4/, taking account of the contribution  
  from the competing processes. The direct components for mt=51   
  and 52 were, calculated with the dwuck/5/. The calculated data  
  for the first level were normalized at 12 MeV to the experimen- 
  tal data/6/.  The level data used in these two calculations were
  taken from ref./7/ as follows:                                  
       mt   level energy(MeV)   spin-parity                       
                0.0                 0+                            
       51       1.3686              2+                            
       52       4.1200              4+                            
       53       4.2384              2+                            
       54       5.2361              3+                            
       55       6.0103              4+                            
       56       6.4322              0+                            
       57       7.3479              2+                            
       58       7.5530              1-                            
       59       7.6162              3-                            
       60       7.7472              1+                            
       61       7.8120              3+                            
  Levels above 10.0 MeV were assumed to be overlapping.           
 mt=16, 22, 28, 103, 107     (n,2n), (n,na), (n,np), (n,p), (n,a) 
   Calculated with the gnash code/8/ using the above optical model
   parameters.  The (n,2n) cross sections were modified so as to  
   fit to the experimental data.                                  
 mt=102      Capture                                              
   Calculated with the casthy code/4/ and normalized to 1.8 mb    
   at 30 keV.                                                     
mf=4  Angular distributions of secondary neutrons                 
   Calculated with the casthy code/4/.                            
   Calculated with the casthy code/4/, and contributions from the 
   direct process calculated with the dwuck code/5/ were added to 
   mt=51 and 52.                                                  
   Calculated with the casthy code/4/ and transformed into the    
   laboratory system.                                             
 mt=16, 22, 28                                                    
   Assumed to be isotoropic in the laboratory system.             
mf=5  Energy distributions of secondary neutrons                  
 mt=16, 22, 28, 91                                                
   Calculated with the gnash code/8/.                             
mf=12 Photon multiplicities and transition probabilities          
   Calculated with gnash.                                         
   Stored under option-2 (transition probability array).          
   Calculated with casthy.                                        
mf=14 Photon angular distributions                                
mf=15 Continuous photon energy spectra                            
   Calculated with gnash.                                         
   Calculated with casthy.  Between 44 and 430 keV, the data      
   measured at Tokyo Institute of Technology /9/ were inserted.   
1) Mughabghab S.F. and Garber D.I. :"Neutron cross sections", Vol.
   1, Part B (1984).                                              
2) Hibdon C.T. : taken from exfor (1969).                         
3) Singh U.N. et al. : Phys. Rev. C10, 2150 (1974).               
4) Igarasi S. : J. Nucl. Sci. Tech. 12, 67 (1975).                
5) Kunz P.D. : unpublished.                                       
6) Foertsch et al. : Nucl. Instr. Meth. 169, 533 (1980).          
7) ENSDF(Evaluated Nuclear Structure Data File)                   
8) Young P.G. and Arthur E.D. : LA-6947 (1977).                   
9) Igashira M.: private communication (2000).