97-Bk-249

 97-BK-249 JAERI      EVAL-MAR85 Y.KIKUCHI AND T.NAKAGAWA         
JAERI-M 85-138        DIST-SEP89                                  
----JENDL-3.2         MATERIAL 9752                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
HISTORY                                                           
85-03 NEW EVALUATION FOR JENDL-3 WAS MADE BY Y.KIKUCHI AND        
      T.NAKAGAWA (JAERI).  DETAILS ARE GIVEN IN REF. /1/.         
88-02 DATA WERE CHECKED AND COPIED INTO JENDL-3.                  
                                                                  
MF=1  GENERAL INFORMATION                                         
  MT=451   COMMENTS AND DICTIONARY                                
  MT=452   NUMBER OF NEUTRONS PER FISSION                         
             SUM OF MT'S =455 AND 456.                            
  MT=455   DELAYED NEUTRON DATA                                   
             SEMI-EMPIRICAL FORMULA BY TUTTLE /2/.                
  MT=456   DELAYED NEUTRON DATA                                   
             SEMI-EMPIRICAL FORMULA BY HOWERTON /3/.              
                                                                  
MF=2,MT=151  RESONANCE PARAMETERS                                 
  RESOLVED RESONANCES FOR MLBW FORMULA : 1.0E-5 EV TO 60 EV       
    RESONANCE ENERGIES, NEUTRON AND RADIATIVE WIDTHS WERE TAKEN   
    FROM THE EXPERIMENTAL DATA OF BENJAMIN+ /4/.  FOR RESONANCES  
    WHOSE RADIATIVE WIDTH WAS UNKNOWN, THE AVERAGE VALUE OF 0.0357
    EV /4/ WAS ADOPTED.  FISSION WIDTH OF 0.0002 EV WAS ESTIMATED 
    FROM THE THERMAL FISSION CROSS SECTION, WHICH WAS ESTIMATED   
    FROM THE SYSTEMATICS OF CAPTURE TO FISSION RATIO BY PRINCE/5/.
    THE PARAMETERS OF THE NEGATIVE RESONANCE WERE ADJUSTED SO AS  
    TO REPRODUCE THE THERMAL CROSS SECTIONS. NO BACKGROUND        
    CORRECTION WAS APPLIED.                                       
                                                                  
  UNRESOLVED RESONANCES : 60 EV - 30 KEV                          
    OBTAINED FROM OPTICAL MODEL CALCULATION:                      
        S1=3.0E-4  ,S2=0.83E-4  ,R=9.07 FM.                       
    ESTIMATED FROM RESOLVED RESONANCES:                           
        DOBS=1.16 EV, GAM-G=35.7 MILLI-EV ,S0=1.13E-4             
        GAM-F=0.2 MILLI-EV.                                       
                                                                  
  CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS      
                   2200 M/S VALUE           RES. INT.             
      TOTAL         717.5    B                 -                  
      ELASTIC         3.93   B                 -                  
      FISSION         3.96   B                12.1 B              
      CAPTURE       709.6    B              1130   B              
                                                                  
MF=3  NEUTRON CROSS SECTIONS                                      
  MT=1,2,4,51-68,91,102,251   SIG-T,SIG-EL,SIG-IN,SIG-C,MU-BAR    
        CALCULATED WITH OPTICAL AND STATISTICAL MODELS.           
        OPTICAL POTENTIAL PARAMETERS WERE OBTAINED 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)          
        STATISTICAL MODEL CALCULATION WITH CASTHY CODE /7/.       
           COMPETING PROCESSES : FISSION,(N,2N),(N,3N),(N,4N).    
           LEVEL FLUCTUATION CONSIDERED.                          
        THE LEVEL SCHEME TAKEN FROM REF. /8/.                     
                   NO.        ENERGY(KEV)   SPIN-PARITY           
                  G.S.             0           7/2 +              
                    1              8.8         3/2 -              
                    2             39.6         5/2 -              
                    3             41.8         9/2 +              
                    4             82.6         7/2 -              
                    5             93.74       11/2 +              
                    6            137.7         9/2 -              
                    7            155.84       13/2 +              
                    8            204.6        11/2 -              
                    9            229.3        15/2 +              
                   10            283.0        13/2 -              
                   11            313.0        17/2 +              
                   12            372.8        15/2 -              
                   13            377.6         1/2 +              
                   14            389.2         5/2 +              
                   15            410.6         3/2 +              
                   16            421.3         5/2 +              
                   17            428.9         7/2 +              
                   18            474.9         9/2 +              
                CONTINUUM LEVELS ASSUMED ABOVE  519 KEV.          
        THE LEVEL DENSITY PARAMETERS : GILBERT AND CAMERON /9/.   
        GAMMA-RAY STRENGTH FUNCTION OF 3.2E-2 DEDUCED FROM        
        RESONANCE PARAMETERS.                                     
                                                                  
  MT=16,17,37      (N,2N),(N,3N),(N,4N)                           
        CALCULATED WITH EVAPORATION MODEL.                        
                                                                  
  MT=18            FISSION                                        
        EVALUATED ON THE BASIS OF THE MEASURED DATA BY            
        SILBERT/10/, VOROTONIKOV+/11/ AND FOMUSHKIN+ /12/.        
                                                                  
MF=4  ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS                 
  MT=2,51-68          CALCULATED WITH OPTICAL MODEL.              
  MT=16,17,18,37,91   ISOTROPIC IN THE LABORATORY SYSTEM.         
                                                                  
MF=5  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS                  
  MT=16,17,37,91      EVAPORATION SPECTRUM.                       
  MT=18               MAXWELLIAN FISSION SPECTRUM.                
                      TEMPERATURE ESTIMATED FROM SYSTEMATICS OF   
                      SMITH+/13/.                                 
                                                                  
REFERENCES                                                        
 1) KIKUCHI Y. AND NAKAGAWA T.: JAERI-M 85-138 (1985).            
 2) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, P.29 (1979).            
 3) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).               
 4) BENJAMIN R.W. ET AL.: NUCL. SCI. ENG., 85, 261 (1983).        
 5) PRINCE A.: TRANS. AM. NUCL. SOC., 10, 228 (1967)              
 6) PHILLIPS T.W. AND HOWE F.R.: NUCL. SCI. ENG., 69, 375 (1979). 
 7) IGARASI S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).            
 8) LEDERER C.M. AND SHIRLEY V.S.: TABLE OF ISOTOPES , 7TH ED.    
 9) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446 (1965).
10) SILBERT M.G.: NUCL. SCI. ENG., 63, 198 (1977).                
11) VOROTNIKOV I.V. ET AL.: SOV. J. NUCL. PHYS., 10, 419 (1970).  
12) FOMSHKIN E.F. ET AL.: SOV. J. NUCL. PHYS., 14, 41(1972).      
13) SMITH A.B. ET AL.: ANL/NDM-50 (1979).