56-Ba-138

 56-BA-138 JNDC       EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.        
                      DIST-SEP90 REV2-OCT93                       
----JENDL-3.2         MATERIAL 5649                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
HISTORY                                                           
84-10 EVALUATION FOR JENDL-2 WAS MADE BY JNDC FPND W.G./1/        
90-03 MODIFICATION FOR JENDL-3 WAS MADE/2/.                       
93-10 JENDL-3.2 WAS MADE BY JNDC FPND W.G.                        
                                                                  
     *****   MODIFIED PARTS FOR JENDL-3.2   ********************  
      (2,151)       RESOLVED RESONANCE PARAMETERS                 
      (3,102)       RE-NORMALIZATION                              
      (3,2), (3,4), (3,51-91) AND ANGULAR DISTRIBUTIONS           
                    SMALL EFFECTS OF THE RE-NORMALIZATION OF      
                    CAPTURE CROSS SECTION. ( < 0.3% )             
     ***********************************************************  
                                                                  
                                                                  
MF = 1  GENERAL INFORMATION                                       
  MT=451 COMMENTS AND DICTIONARY                                  
                                                                  
MF = 2  RESONANCE PARAMETERS                                      
  MT=151 RESOLVED AND UNRESOLVED RESONANCE PARAMETERS             
  RESOLVED RESONANCE PARAMETERS FOR MLBW FORMULA (BELOW 100 KEV)  
       FOR JENDL-2, EVALUATION WAS MADE BY KIKUCHI /3/ MAINLY ON  
    THE BASIS OF THE DATA MEASURED BY MUSGROVE ET AL./4/ UP TO 92 
    KEV.  ABOVE 100 KEV, NEUTRON WIDTHS WERE ADOPTED FROM BILPUCH 
    ET AL./5/  AVERAGE CAPTURE WIDTHS WERE ASSUMED TO BE 0.055+-  
    0.020 EV FOR S-WAVE RESONANCES AND 0.045+-0.020 EV FOR P-WAVE 
    ONES, AND TO BE 0.095 EV IN THE ENERGY RANGE ABOVE 100 KEV.  A
    NEGATIVE RESONANCE WAS ADDED AT -6.22 KEV SO AS TO REPRODUCE  
    THE CAPTURE CROSS SECTION OF 0.360+-0.036 BARNS AT 0.0253     
    EV/6/.                                                        
      FOR JENDL-3, 10 RESONANCES WERE NEWLY ASIGNED BY TAKING THE 
    EXPERIMENTAL DATA BY MIZUMOTO/7/ IN THE ENERGY RANGE FROM 648 
    EV TO 63.12 KEV.  TOTAL SPIN J OF SOME RESONANCES WAS TENTA-  
    TIVELY ESTIMATED WITH A RANDOM NUMBER METHOD                  
                                                                  
  NO UNRESOLVED RESONANCE REGION                                  
                                                                  
  CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)   
                     2200 M/S               RES. INTEG.           
      TOTAL           5.9090                   -                  
      ELASTIC         5.5499                   -                  
      CAPTURE         0.3591                    0.265             
                                                                  
MF = 3  NEUTRON CROSS SECTIONS                                    
  BELOW 100 KEV, RESONANCE PARAMETERS WERE GIVEN.                 
  ABOVE 100 KEV, THE SPHERICAL OPTICAL AND STATISTICAL MODEL      
  CALCULATION WAS PERFORMED WITH CASTHY/8/, BY TAKING ACCOUNT OF  
  COMPETING REACTIONS, OF WHICH CROSS SECTIONS WERE CALCULATED    
  WITH PEGASUS/9/ STANDING ON A PREEQUILIBRIUM AND MULTI-STEP     
  EVAPORATION MODEL.  THE OMP'S FOR NEUTRON GIVEN IN TABLE 1 WERE 
  DETERMINED TO REPRODUCE A SYSTEMATIC TREND OF THE BA-NAT. TOTAL 
  CROSS SECTION BY CHANGING WS AND RSO OF IIJIMA-KAWAI POTENTIAL  
  /10/.  THE OMP'S FOR CHARGED PARTICLES ARE AS FOLLOWS:          
     PROTON   = PEREY/11/                                         
     ALPHA    = HUIZENGA AND IGO/12/                              
     DEUTERON = LOHR AND HAEBERLI/13/                             
     HELIUM-3 AND TRITON = BECCHETTI AND GREENLEES/14/            
  PARAMETERS FOR THE COMPOSITE LEVEL DENSITY FORMULA OF GILBERT   
  AND CAMERON/15/ WERE EVALUATED BY IIJIMA ET AL./16/  MORE       
  EXTENSIVE DETERMINATION AND MODIFICATION WERE MADE IN THE       
  PRESENT WORK.  TABLE 2 SHOWS THE LEVEL DENSITY PARAMETERS USED  
  IN THE PRESENT CALCULATION.  ENERGY DEPENDENCE OF SPIN CUT-OFF  
  PARAMETER IN THE ENERGY RANGE BELOW E-JOINT IS DUE TO GRUPPELAAR
  /17/.                                                           
                                                                  
  MT = 1  TOTAL                                                   
    SPHERICAL OPTICAL MODEL CALCULATION WAS ADOPTED.              
                                                                  
  MT = 2  ELASTIC SCATTERING                                      
    CALCULATED AS (TOTAL - SUM OF PARTIAL CROSS SECTIONS).        
                                                                  
  MT = 4, 51 - 91  INELASTIC SCATTERING                           
    SPHERICAL OPTICAL AND STATISTICAL MODEL CALCULATION WAS       
    ADOPTED.  THE LEVEL SCHEME WAS TAKEN FROM REF./18/.           
                                                                  
           NO.      ENERGY(MEV)    SPIN-PARITY    DWBA CAL.       
           GR.       0.0             0  +                         
            1        1.4359          2  +             *           
            2        1.8987          4  +                         
            3        2.0907          6  +                         
            4        2.1896          2  +                         
            5        2.2032          6  +                         
            6        2.2180          2  +                         
            7        2.3077          4  +                         
            8        2.4156          5  +                         
            9        2.4457          3  +                         
           10        2.5832          1  +                         
           11        2.5840          4  +                         
           12        2.6396          2  +                         
           13        2.7795          4  +                         
           14        2.8517          3  +                         
           15        2.8810          3  -             *           
           16        2.9315          1  +                         
           17        2.9912          3  +                         
           18        3.0500          2  +                         
           19        3.1560          4  +                         
      LEVELS ABOVE 3.164 MEV WERE ASSUMED TO BE OVERLAPPING.      
                                                                  
    FOR THE LEVELS WITH AN ASTERISK, THE CONTRIBUTION OF DIRECT   
    INELASTIC SCATTERING CROSS SECTIONS WAS CALCULATED BY THE     
    DWUCK-4 CODE/19/.  DEFORMATION PARAMETERS (BETA2 = 0.0925 AND 
    BETA3 = 0.118) WERE BASED ON THE DATA COMPILED BY RAMAN ET    
    AL./20/ AND SPEAR/21/, RESPECTIVELY.                          
                                                                  
  MT = 102  CAPTURE                                               
    SPHERICAL OPTICAL AND STATISTICAL MODEL CALCULATION WITH      
    CASTHY WAS ADOPTED.  DIRECT AND SEMI-DIRECT CAPTURE CROSS     
    SECTIONS WERE ESTIMATED ACCORDING TO THE PROCEDURE OF BENZI   
    AND REFFO/22/ AND NORMALIZED TO 1 MILLI-BARN AT 14 MEV.       
                                                                  
    THE GAMMA-RAY STRENGTH FUNCTION (2.54E-06) WAS ADJUSTED TO THE
    CAPTURE CROSS SECTION OF 2.7 MILLI-BARNS AT 700 KEV SO AS TO  
    REPRODUCE THE CROSS SECTION MEASURED BY JOHNSRUD ET AL./23/   
    AND STAVISSKIJ AND TOLSTIKOV/24/                              
                                                                  
  MT = 16  (N,2N) CROSS SECTION                                   
  MT = 17  (N,3N) CROSS SECTION                                   
  MT = 22  (N,N'A) CROSS SECTION                                  
  MT = 28  (N,N'P) CROSS SECTION                                  
  MT =103  (N,P) CROSS SECTION                                    
  MT =104  (N,D) CROSS SECTION                                    
  MT =105  (N,T) CROSS SECTION                                    
  MT =107  (N,ALPHA) CROSS SECTION                                
    THESE REACTION CROSS SECTIONS WERE CALCULATED WITH THE        
    PREEQUILIBRIUM AND MULTI-STEP EVAPORATION MODEL CODE PEGASUS. 
                                                                  
    THE KALBACH'S CONSTANT K (= 144.6) WAS ESTIMATED BY THE       
    FORMULA DERIVED FROM KIKUCHI-KAWAI'S FORMALISM/25/ AND LEVEL  
    DENSITY PARAMETERS.                                           
                                                                  
    FINALLY, THE (N,2N), (N,P) AND (N,ALPHA) CROSS SECTIONS WERE  
    NORMALIZED TO THE FOLLOWING VALUES AT 14.5 MEV:               
      (N,2N)      1750.00  MB (SYSTEMATICS OF WEN DEN LU+/26/)    
      (N,P)          2.80  MB (MEASURED BY IKEDA+/27/)            
      (N,ALPHA)      2.10  MB (MEASURED BY IKEDA+)                
                                                                  
  MT = 251  MU-BAR                                                
    CALCULATED WITH CASTHY.                                       
                                                                  
MF = 4  ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS               
  LEGENDRE POLYNOMIAL COEFFICIENTS FOR ANGULAR DISTRIBUTIONS ARE  
  GIVEN IN THE CENTER-OF-MASS SYSTEM FOR MT=2 AND DISCRETE INELAS-
  TIC LEVELS, AND IN THE LABORATORY SYSTEM FOR MT=91.  THEY WERE  
  CALCULATED WITH CASTHY.  CONTRIBUTION OF DIRECT INELASTIC       
  SCATTERING WAS CALCULATED WITH DWUCK-4.  FOR OTHER REACTIONS,   
  ISOTROPIC DISTRIBUTIONS IN THE LABORATORY SYSTEM WERE ASSUMED.  
                                                                  
MF = 5  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS                
  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS WERE CALCULATED WITH 
  PEGASUS FOR INELASTIC SCATTERING TO OVERLAPPING LEVELS AND FOR  
  OTHER NEUTRON EMITTING REACTIONS.                               
                                                                  
TABLE 1  NEUTRON OPTICAL POTENTIAL PARAMETERS                     
                                                                  
                DEPTH (MEV)       RADIUS(FM)    DIFFUSENESS(FM)   
         ----------------------   ------------  ---------------   
        V  = 41.8                 R0 = 6.89     A0 = 0.62         
        WS = 2.95+0.789E          RS = 7.098    AS = 0.35         
        VSO= 7.0                  RSO= 6.89     ASO= 0.62         
  THE FORM OF SURFACE ABSORPTION PART IS DER. WOODS-SAXON TYPE.   
                                                                  
TABLE 2  LEVEL DENSITY PARAMETERS                                 
                                                                  
 NUCLIDE       A(1/MEV)  T(MEV)    C(1/MEV)  EX(MEV)   PAIRING    
 ---------------------------------------------------------------  
 54-XE-134     1.400E+01 6.300E-01 3.184E-01 5.224E+00 1.820E+00  
 54-XE-135     1.550E+01 5.565E-01 7.506E-01 4.010E+00 1.120E+00  
 54-XE-136     1.400E+01 6.500E-01 3.270E-01 5.679E+00 1.970E+00  
 54-XE-137     1.550E+01 5.565E-01 7.470E-01 4.010E+00 1.120E+00  
                                                                  
 55-CS-135     1.343E+01 6.537E-01 1.831E+00 4.203E+00 7.000E-01  
 55-CS-136     1.400E+01 6.000E-01 4.424E+00 2.967E+00 0.0        
 55-CS-137     1.336E+01 6.200E-01 9.986E-01 3.836E+00 8.500E-01  
 55-CS-138     1.470E+01 5.737E-01 4.715E+00 2.858E+00 0.0        
                                                                  
 56-BA-136     1.610E+01 6.500E-01 5.721E-01 6.928E+00 2.280E+00  
 56-BA-137     1.645E+01 5.640E-01 5.394E-01 4.905E+00 1.580E+00  
 56-BA-138     1.390E+01 7.200E-01 4.123E-01 7.233E+00 2.430E+00  
 56-BA-139     2.022E+01 4.800E-01 5.326E-01 4.629E+00 1.580E+00  
 ---------------------------------------------------------------  
                                                                  
 SPIN CUTOFF PARAMETERS WERE CALCULATED AS 0.146*SQRT(A)*A**(2/3).
 IN THE CASTHY CALCULATION, SPIN CUTOFF FACTORS AT 0 MEV WERE     
 ASSUMED TO BE 7.914 FOR BA-138 AND 5.0 FOR BA-139.               
                                                                  
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    (1987)                                                        
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