96-Cm-250

 96-CM-250 JAERI      EVAL-OCT95 T.NAKAGAWA AND T.LIU             
                      DIST-MAR02 REV3-DEC00            20001213   
----JENDL-3.3         MATERIAL 9655                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
HISTORY                                                           
87-08 EVALUATION WAS MADE BY N. TAKAGI (TOKYO INSTITUTE OF        
      TECHNOLOGY, TIT) /1/.                                       
89-08 CROSS SECTIONS WERE MODIFIED BELOW 90 EV.                   
94-06 JENDL-3.2.                                                  
       NU-P, NU-D AND NU-TOTAL WERE MODIFIED.                     
      COMPILED BY T.NAKAGAWA (NDC/JAERI)                          
95-10 NEW EVALUATION FOR JENDL ACTINIDE FILE WAS MADE BY          
      T.NAKAGAWA AND T.LIU.                                       
00-04 MODIFICATION WAS MADE AND COMPILED BY T.NAKAGAWA            
                                                                  
     ***** Modified parts from JENDL-3.2 *******************      
     ALL DATA of Mf's = 2, 3, 4 and 5.                            
     *******************************************************      
                                                                  
                                                                  
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                                   
      AVERAGE VALUES OF SYSTEMATICS BY TUTTLE/2/, BENEDETTI ET    
      AL./3/ AND WALDO ET AL./4/                                  
  MT=456 PROMPT NEUTRONS PER FISSION                              
      BASED ON SYSTEMATICS BY MANERO AND KONSHIN/5/, AND BY       
      HOWERTON/6/.                                                
                                                                  
MF=2,MT=151  RESONANCE PARAMETERS                                 
  RESOLVED RESONANCES FOR MLBW 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 = 180 EV, RADIATIVE CAPTURE WIDTH = 0.04 EV,          
        S-0 = 1.0E-4, Ratio of neutron to fission widths = 1.0E-4,
        R = 9.21 FM.                                              
    PARAMETERS OF THE NEGATIVE AND FIRST POSITIVE LEVELS WERE     
    ADJUSTED SO AS TO REPRODUCE THE THERMAL CROSS SECTIONS:       
        Fission = 0.002 b estimated from systematics              
        Capture = about 80 b /7/                                  
                                                                  
  UNRESOLVED RESONANCES: 150 eV TO 30 keV                         
    S-0 = 1.0E-4, S-1 = 3.0E-4, D-0=180 eV, R = 8.998 fm,         
    Radiative width = 0.04 EV, Energy dependent fission width to  
    reproduce the fission cross section estimated.                
                                                                  
  CALCULATED 2200 M/S CROSS SECTIONS AND RESONANCE INTEGRALS      
                   2200 M/S VALUE           RES. INT.             
      TOTAL         124.9    B                                    
      ELASTIC        39.5    B                                    
      FISSION         0.002  B                 6.91  B            
      CAPTURE        85.3    B               304     B            
                                                                  
MF=3  NEUTRON CROSS SECTIONS                                      
  MT=1 TOTAL CROSS SECTION                                        
      CALCULATED WITH CASTHY CODE /8/ BASED ON THE SHERICAL       
      OPTICAL MODEL. THE OPTICAL POTENTIAL OF REF./9/ WERE        
      USED.                                                       
                                                                  
           V = 45.036-0.3*EN                        (MEV)         
           WS= 4.115+0.4*EN                         (MEV)         
           WV= 0             , VSO = 7.5            (MEV)         
           R = RSO = 1.256   , RS  = 1.260           (FM)         
           A = ASO = 0.626   , B   = 0.555+0.0045*EN (FM)         
                                                                  
      COMPETING PROCESSES OF THE FISSION, (N,2N) AND (N,3N) WERE  
      TAKEN INTO ACCOUNT.  THE FOLLOWING LEVEL DENSITY PARAMETERS 
      OF GILBERT-CAMERON'S FORMULA /10/ WERE USED.                
                                                                  
                 ISOTOPE        CM-250         CM-251             
                A(1/MEV)        30.0          28.2185             
        SPIN-CUTOFF PARA.       31.74         30.86               
          PAIRING E(MEV)         1.585         0.72               
             TEMP. (MEV)         0.40          0.3748             
                C(1/MEV)         1.6351        4.3075             
                 EX(MEV)         5.0821        3.6489             
                                                                  
        THE LEVEL SCHEME TAKEN FROM REF. /11/                     
                   NO.        ENERGY(KEV)   SPIN-PARITY           
                  G.S.             0.0           0 +              
                    1.            43.0           2 +              
                    2.           142.0           4 +              
                CONTINUUM LEVELS ASSUMED ABOVE 160 KEV.           
                                                                  
  MT= 2         ELASTIC SCATTERING                                
      CALCULATED AS TOTAL - PARTIAL CROSS SECTIONS.               
                                                                  
  MT= 4         TOTAL INELASTIC SCATTERING                        
      SUM OF MT=51 to 52 AND 91.                                  
                                                                  
  MT=16,17      (N,2N), (N,3N) CROSS SECTIONS                     
        STAPRE RESULTS CALCULATED BY KONSHIN /12/ were adopted.   
                                                                  
  MT=18          FISSION CROSS SECTION                            
        Above 700 keV, Konshin's calculation /12/ with STAPRE     
        was adopted. Below 700 keV, estimated by eye-guiding.     
                                                                  
  MT=51, 52      Inelastic scattering                             
        CALCULATED BY ECIS /13/ AND CASTHY /8/ CODES.             
        LAGRANGE'S DEFORMED OPTICAL POTENTIAL PARAMETERS /14/     
        WERE USED.                                                
           V  = 49.82 - 17*((N-Z)/A) - 0.3*EN (MEV)               
           WS =  5.52 - 9*((N-Z)/A) + 0.4*EN (MEV)   EN=<10 MEV   
              =  9.52 - 9*((N-Z)/A) (MEV)     10 =< EN <=20 MEV   
           VSO = 6.2                                              
           R = RS = 1.26, RSO = 1.12 (FM)                         
           A = 0.63, AS = 0.52, ASO = 0.47 (FM)                   
           BETA-2 = 0.204, BETA-4 = 0.051                         
                                                                  
        Statistical model calculation with CASTHY code was made by
        using the above-mentioned parameters.                     
                                                                  
  MT=91          Inelastic scattering to continuum levels         
        CALCULATED WITH CASTHY CODE /8/ and modified to a         
        decreasing curve above 10 MeV.                            
                                                                  
  MT=102         RADIATIVE CAPTURE                                
        CALCULATED WITH CASTHY CODE/8/.                           
        DIRECT AND SEMI-DIRECT CAPTURE CROSS SECTIONS WERE        
        ESTIMATED with DSD code /15/.                             
                                                                  
MF=4  ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS                 
  MT=2                                                            
      BELOW 300 KEV: CALCULATED WITH CASTHY CODE /8/              
      ABOVE 500 KEV: CALCULATED WITH ECIS CODE /13/               
                                                                  
  MT=16,17,18                                                     
      ASSUMED TO BE ISOTROPIC IN THE LABORATORY SYSTEM.           
                                                                  
  MT=51,52                                                        
      SUM OF ECIS AND CASTHY CALCULATIONS.                        
                                                                  
  MT=91                                                           
      CALCULATED WITH CASTHY CODE.                                
                                                                  
                                                                  
MF=5  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS                  
  MT=16,17,91                                                     
      CALCULATED WITH EGNASH /16/.                                
                                                                  
  MT=18                                                           
      MAXWELLIAN FISSION SPECTRUM WITH TEMPERATURE ESTIMATED FROM 
      SYSTEMATICS OF HOWERTON AND DOYAS /17/.  THE RATIOS OF      
      MULTI-CHANCE FISSION TO TOTAL WERE ESTIMATED FROM STAPRE    
      CALCULATION/12/.                                            
                                                                  
                                                                  
REFERENCES                                                        
 1) TAKAGI N. ET AL.: J. NUCL. SCI. TECHNOL., 27, 853 (1990).     
 2) TUTTLE R.J.: INDC(NDS)-107/G+SPECIAL, P.29 (1979),            
 3) BENEDETTI G. ET AL.: NUCL. SCI. ENG., 80, 379 (1982).         
 4) WALDO R. ET AL.: PHYS. REV., C23, 1113 (1981).                
 5) MANERO F. AND KONSHIN V.A.:  AT. ENERGY REV.,10, 637 (1972).  
 6) HOWERTON R.J.: NUCL. SCI. ENG., 62, 438 (1977).               
 7) Lougheed R.W. et al.: BNL-NCS-22500, 99 (1977).               
 8) IGARASI S. AND FUKAHORI T.: JAERI 1321 (1991),                
 9) IGNATYUK A.V. ET AL.: SOV. J. NUCL. PHYS., 42, 360 (1985).    
10) GILBERT A. AND CAMERON A.G.W.: CAN. J. PHYS., 43, 1446(1965). 
11) SCHMORAK M.R.: NUCL. DATA SHEETS, 57, 515 (1989).             
12) KONSHIN V.A.: JAERI-RESEARCH 95-010 (1995).                   
13) RAYNAL J.: IAEA SMR-9/8 (1970).                               
14) LAGRANGE CH. and JARY J.: NEANDC(E) 198 "L" (1978).           
15) Kawano T.: private communication (1999).                      
16) YAMAMURO. N.: JAERI-M 90-006 (1990).                          
    Young P.G. and Arthur E.D.: LA-6947 (1977).                   
17) HOWERTON R.J. AND DOYAS R.J.: NUCL. SCI. ENG., 46, 414        
    (1971).