98-Cf-250

 98-CF-250 JAERI      EVAL-MAR86 T.NAKAGAWA                       
 JAERI-M 86-086       DIST-SEP89                                  
----JENDL-3.2         MATERIAL 9855                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
HISTORY                                                           
86-03 NEW EVALUATION WAS MADE BY T.NAKAGAWA (JAERI).              
      DETAILS ARE DESCRIBED IN REF. /1/.                          
                                                                  
MF=1  GENERAL INFORMATION                                         
  MT=451   COMMENTS AND DICTIONARY                                
  MT=452   NUMBER OF NEUTRONS PER FISSION                         
             SUM OF MT=455 AND MT=456                             
  MT=455   DELAYED NEUTRON DATA                                   
             BASED ON SEMI-EMPIRICAL FORMULA BY TUTTLE /2/.       
  MT=456   NUMBER OF PROMPT NEUTRONS PER FISSION                  
             BASED ON SEMI-EMPIRICAL FORMULA BY HOWERTON /3/.     
                                                                  
MF=2,MT=151  RESONANCE PARAMETERS                                 
  RESOLVED RESONANCES FOR SLBW FORMULA : 1.0E-5 EV TO 150 EV      
    HYPOTHETICAL RESONANCE LEVELS WERE GENERATED, AND THEIR       
    PARAMETERS WERE DETERMINED FROM THE ASSUMED AVERAGE PARAMETERS
        D-0 = 16 EV,  RADIATIVE CAPTURE WIDTH = 0.0369 EV,        
        S-0 = 1.0E-4, FISSION WITH = 0.0001 EV, R = 9.252 FM.     
    PARAMETERS OF THE NEGATIVE AND FIRST POSITIVE LEVELS WERE     
    ADJUSTED SO AS TO REPRODUCE THE THERMAL CROSS SECTIONS AND    
    RESONANCE INTEGRALS.                                          
  UNRESOLVED RESONANCES                : 150 EV TO 30 KEV         
    S-0 = 1.0E-4, S-1 = 3.3E-4, D-0=16 EV, R = 9.11 FM,           
    RADIATIVE WIDTH = 0.0369 EV, FISSION WIDTH = 0.0001 EV.       
    THE SCATTERING RADIUS WAS ADJUSTED SLIGHTLY.                  
                                                                  
  CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS      
                   2200 M/S VALUE           RES. INT.             
      TOTAL        1950.7    B                 -                  
      ELASTIC       167.4    B                 -                  
      FISSION         4.09   B                27.8 B              
      CAPTURE      1779.2    B              8420   B              
                                                                  
MF=3  NEUTRON CROSS SECTIONS                                      
  MT=1   TOTAL                                                    
  MT=2   ELASTIC SCATTERING                                       
  MT=4, 51 TO 79 AND 91 INELASTIC SCATTERING                      
  MT=102 RADIATIVE CAPTURE                                        
  MT=251 MU-BAR                                                   
    CALCULATED WITH THE PROGRAM CASTHY /4/ BASED ON THE OPTICAL   
    AND STATISTICAL MODELS.  OPTICAL POTENTIAL PARAMETERS WERE    
    OBTAINED /5/ BY FITTING THE TOTAL CROSS SECTION OF PHILLIPS   
    AND HOWE /6/ FOR AM-241:                                      
           V = 43.4 - 0.107*EN                      (MEV)         
           WS= 6.95 - 0.339*EN + 0.0531*EN**2       (MEV)         
           WV= 0             , VSO = 7.0            (MEV)         
           R = RSO = 1.282   , RS = 1.29            (FM)          
           A = ASO = 0.60    , B  = 0.5             (FM)          
    IN THE STATISTICAL CALCULATION, LEVEL FLUCTUATION AND         
    COMPETING PROCESS (FISSION, (N,2N) AND (N,3N)) WERE TAKEN INTO
    ACCOUNT.  THE LEVEL SCHEME WAS TAKEN FROM REF. /7/.           
          NO.  ENERGY(KEV) J-PARITY     NO.  ENERGY(KEV) J-PARITY 
         -------------------------     ------------------------   
         GROUND    0.0        0 +       15    1209.98       2 -   
           1      42.722      2 +       16    1211.         3 -   
           2     141.886      4 +       17    1244.51       2 +   
           3     296.25       6 +       18    1255.47       4 -   
           4     871.64       2 -       19    1266.65       0 +   
           5     905.90       3 -       20    1296.64       2 +   
           6     952.07       4 -       21    1311.07       5 -   
           7    1008.6        5 -       22    1335.         3 -   
           8    1031.85       2 +       23    1377.83       6 -   
           9    1070.         6 -       24    1385.49      (1 +)  
          10    1071.38       3 +       25    1396.16       5 -   
          11    1123.         4 +       26    1411.34      (1 +)  
          12    1154.23       0 +       27    1426.86       3 -   
          13    1175.52       1 -       28    1457.83       6 -   
          14    1189.40       2 +       29    1478.45       5 -   
         -------------------------     ------------------------   
            LEVELS ABOVE 1.50 MEV WERE ASSUMED TO BE OVERLAPPING. 
    THE LEVEL DENSITY PARAMETERS WERE DERIVED FROM RESONANCE LEVEL
    SPACINGS AND LOW LAYING EXCITED LEVELS ON THE BASIS OF        
    GILBERT-CAMERON'S FOUMULA /8/.  THE AVERAGE RADIATIVE CAPTURE 
    WIDTH OF 0.0369 EV AND S-WAVE LEVEL SPACING OF 16 EV WERE     
    ASSUMED.                                                      
                                                                  
  MT=16 AND 17  (N,2N) AND (N,3N)                                 
    CALCULATED WITH EVAPORATION MODEL.                            
                                                                  
  MT=18   FISSION                                                 
    EVALUATED ON THE BASIS OF THE SYSTEMATICS.                    
                                                                  
MF=4  ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS                 
  MT=2,51-79       CALCULATED WITH OPTICAL MODEL.                 
  MT=16,17,18,91   ISOTROPIC DISTRIBUTIONS IN THE LABORATORY      
      SYSTEM WERE ASSUMED.                                        
                                                                  
MF=5  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS                  
  MT=16,17,91      EVAPORATION SPECTRUM.                          
  MT=18            MAXWELLIAN FISSION SPECTRUM.                   
                      TEMPERATURE ESTIMATED FROM SYSTEMATICS OF   
                      SMITH ET AL./9/.                            
                                                                  
REFERENCES                                                        
 1) NAKAGAWA, T.: JAERI-M 86-086 (1986).                          
 2) TUTTLE, R.J.: INDC(NDS)-107/G+SPECIAL, P.29 (1979).           
 3) HOWERTON, R.J.: NUCL. SCI. ENG., 62, 438 (1977).              
 4) IGARASI, S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).           
 5) IGARASI, S. AND NAKASAWA, T.: JAERI-M 8342 (1979).            
 6) PHILLIPS, T.W. AND HOWE, F.R.: NUCL. SCI. ENG., 69, 375(1979).
 7) SCHMORAK, M.R.: NUCL. DATA SHEETS, 32, 87 (1981).             
 8) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446 (1965).
 9) SMITH A.B. ET AL.: ANL/NDM-50 (1979).