95-Am-242

 95-AM-242 JAERI      EVAL-MAR80 T.NAKAGAWA, S.IGARASI            
JAERI-M 8903 (1980)   DIST-SEP89                                  
----JENDL-3.2         MATERIAL 9546                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
HISTORY                                                           
80-03 NEW EVALUATION WAS MADE BY T.NAKAGAWA AND S.IGARASI(JAERI). 
      DETAILS ARE GIVEN IN REF. /1/.                              
87-04 FORMAT WAS TRANSLATED TO ENDF-5 FORMAT.                     
88-03 SINCE NO RECENT EXPERIMENTAL DATA WERE AVAILABLE, THE DATA  
      OF JENDL-2 WERE ADOPTED FOR JENDL-3.                        
                                                                  
MF=1  GENERAL INFORMATION                                         
  MT=451  COMMENT AND DICTIONARY                                  
  MT=452  NUMBER OF NEUTRONS PER FISSION                          
           SUM OF PROMPT AND DELAYED NEUTRONS.                    
  MT=455  DELAYED NEUTRON DATA                                    
           ESTIMATED FROM TUTTLE'S SEMI-EMPIRICAL FORMULA /2/.    
  MT=456  NUMBER OF PROMPT NEUTRONS PER FISSION                   
           SEMI-EMPIRICAL FORMULA BY HOWERTON /3/                 
             NU-P= 3.268 + 0.172*E(MEV).                          
                                                                  
MF=2  RESONANCE PARAMETERS                                        
  MT=151  NO RESONANCE PARAMETERS                                 
                                                                  
     2200M/S CROSS SECTIONS AND CALCULATED RESONANCE INTEGRALS.   
                         2200 M/SEC    RES. INTEG.                
             TOTAL       7611.44 B         -                      
             ELASTIC       11.44 B         -                      
             FISSION     2100.0  B      1260 B                    
             CAPTURE     5500.0  B       391 B                    
                                                                  
MF=3  NEUTRON CROSS SECTIONS                                      
  MT=1,2,4,51-72,91,102,251      SIG-T,SIG-EL,SIG-IN,SIG-C,MU-BAR 
      BELOW 0.225 EV:                                             
           1/V FORM WAS ASSUMED FOR FISSION AND CAPTURE CROSS     
           SECTIONS.  EFFECTIVE SCATTERING RADIUS OF 9.54 FM WAS  
           USED FOR ELASTIC SCATTERING CROSS-SECTION CALCULATION. 
      ABOVE 0.225 EV:                                             
           OPTICAL AND STATISTICAL MODELS WERE USED.              
           THE SPHERICAL OPTICAL POTENTIAL PARAMETERS (MEV, FM) : 
            V= 42.0 - 0.107*E , R= 1.282 , A= 0.6                 
            WS= 9.0 - 0.339*E + 0.0531*E**2 , R= 1.29 , A= 0.5    
            VSO= 7.0 , R= 1.282 , A= 0.6                          
            STATISTICAL MODEL CALCULATION WITH CASTHY CODE /4/.   
            COMPETING PROCESSES : FISSION,(N,2N) AND (N,3N).      
            LEVEL FLUCTUATION CONSIDERED.  GAM-G = 0.05 EV AND    
            D = 0.45 EV USED FOR CAPTURE CROSS SECTION CALCULATION
            THE LEVEL SCHEME TAKEN FROM THE COMPILATION BY ELLIS  
            AND HAESE /5/.                                        
              NO.     ENERGY(MEV)        SPIN-PARITY              
             G.S.       0.0                1   -                  
               1        0.044              0   -                  
               2        0.049              3   -                  
               3        0.049              5   -                  
               4        0.074              2   -                  
               5        0.113              6   -                  
               6        0.148              4   -                  
               7        0.148              5   -                  
               8        0.190              7   -                  
               9        0.242              3   -                  
              10        0.263              6   -                  
              11        0.263              7   -                  
              12        0.288              4   -                  
              13        0.288              2   -                  
              14        0.325              3   -                  
              15        0.341              5   -                  
              16        0.372              4   -                  
              17        0.410              6   -                  
              18        0.430              5   -                  
              19        0.488              7   -                  
              20        0.500              6   -                  
              21        0.581              7   -                  
              22        0.679              8   -                  
          OVERLAPPING LEVELS ARE ASSUMED ABOVE 0.681 MEV.         
          THE LEVEL DENSITY PARAMETERS OF GILBERT AND CAMERON /6/.
  MT=16,17  (N,2N) AND (N,3N) CROSS SECTIONS                      
          CALCULATED WITH THE EVAPORATION MODEL BY PEARLSTEIN /7/.
  MT=18 FISSION CROSS SECTION                                     
          THE EMPIRICAL FORMULA USED FOR THE AM-242M DATA WAS     
          APPLIED BY SHIFTING THE ENERGY ORIGIN TO -49 KEV.       
                                                                  
MF=4  ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS                 
  MT=2     LEGENDRE COEFFICIENTS ARE GIVEN BY THE OPTICAL AND     
           STATISTICAL MODEL CALCULATIONS.                        
  MT=16,17,18,91 ISOTROPIC DISTRIBUTIONS IN THE CENTER-OF-MASS    
           SYSTEM.                                                
  MT=51-72 ISOTROPIC DISTRIBUTIONS IN THE LABORATORY SYSTEM.      
                                                                  
MF=5  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS                  
  MT=16,17,91 EVAPORATION SPECTRUM                                
  MT=18    FISSION SPECTRUM ESTIMATED FROM Z**2/A SYSTEMATICS BY  
           SMITH ET AL. /8/ BY ASSUMING E(CF-252) = 2.13 MEV.     
                                                                  
REFERENCES                                                        
 1) T. NAKAGAWA AND S. IGARASI : JAERI-M 8903 (1980), IN JAPANESE.
 2) R.J. TUTTLE : INDC(NDS)-107/G+SPECIAL, 29 (1979).             
 3) R.J. HOWERTON : NUCL. SCI. ENG., 62, 438 (1977).              
 4) S. IGARASI : J. NUCL. SCI. TECHNOL., 12, 67(1975).            
 5) Y.A. ELLIS AND R.L. HAESE : NUCL. DATA SHEETS 21, 615 (1977). 
 6) A. GILBERT AND A.G.W. CAMERON : CAN. J. PHYS., 43, 1446       
    (1965).                                                       
 7) S. PEARLSTEIN : NUCL. SCI. ENG., 23, 238 (1965).              
 8) A.B. SMITH ET AL. : ANL/NDM-50 (1979).