64-Gd-157

 64-GD-157 JNDC       EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.        
                      DIST-NOV90                                  
----JENDL-3.2         MATERIAL 6440                               
-----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/.                       
                                                                  
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 303.7 EV) 
    RESONANCE PARAMETERS WERE BASED ON JENDL-2, AND TOTAL SPIN J  
    OF SOME RESONANCES WAS ESTIMATED FOR JENDL-3 WITH A RANDOM    
    NUMBER METHOD.  EVALUATION FOR JENDL-2 WAS MADE ON THE BASIS  
    OF THE DATA MEASURED BY MOLLER ET AL./3/, RIBON/4/ AND        
    KARZHAVINA ET AL./5/  THE AVERAGE RADIATION WIDTH OF 0.121 EV 
    WAS ASSUMED.  THE SCATTERING RADIUS WAS TAKEN FROM MUGHABGHAB 
    AND GARBER/6/                                                 
                                                                  
  UNRESOLVED RESONANCE REGION : 0.3037 KEV - 100 KEV              
    THE NEUTRON STRENGTH FUNCTION S0 WAS BASED ON THE COMPILATION 
    OF MUGHABGHAB/7/, AND S1 AND S2 WERE CALCULATED WITH OPTICAL  
    MODEL CODE CASTHY/8/.  THE OBSERVED LEVEL SPACING WAS         
    DETERMINED TO REPRODUCE THE CAPTURE CROSS SECTION CALCULATED  
    WITH CASTHY.  THE EFFECTIVE SCATTERING RADIUS WAS OBTAINED    
    FROM FITTING TO THE CALCULATED TOTAL CROSS SECTION AT 100 KEV.
    THE RADIATION WIDTH GG WAS BASED ON THE COMPILATION OF        
    MUGHABGHAB.                                                   
                                                                  
  TYPICAL VALUES OF THE PARAMETERS AT 70 KEV:                     
    S0 = 1.900E-4, S1 = 1.100E-4, S2 = 2.300E-4, SG = 233.E-4,    
    GG = 0.097 EV, R  = 6.881 FM.                                 
                                                                  
  CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)   
                     2200 M/S               RES. INTEG.           
      TOTAL      255085                        -                  
      ELASTIC      1007                        -                  
      CAPTURE    254078                       763                 
     (N,ALPHA)        4.775E-04                                   
                                                                  
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, 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 
  ADOPTED FROM IIJIMA AND KAWAI/10/, AND WS WAS CHANGED.  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                    
           GR.       0.0            3/2 -                         
            1        0.0545         5/2 -                         
            2        0.0640         5/2 +                         
            3        0.1158         7/2 +                         
            4        0.1315         7/2 -                         
            5        0.1810         9/2 +                         
            6        0.2274         9/2 -                         
            7        0.3460        11/2 -                         
            8        0.3600        13/2 +                         
            9        0.4250        11/2 -                         
           10        0.4366         5/2 -                         
           11        0.4772         3/2 +                         
           12        0.5170         7/2 -                         
           13        0.5270         5/2 +                         
           14        0.6170         9/2 -                         
           15        0.6390        15/2 -                         
           16        0.6830         3/2 +                         
           17        0.6850         1/2 +                         
           18        0.6870         3/2 +                         
           19        0.7000         3/2 -                         
           20        0.7040         1/2 -                         
           21        0.7210         9/2 +                         
           22        0.7450         3/2 -                         
           23        0.7510         5/2 -                         
           24        0.7650         7/2 -                         
           25        0.7910         5/2 -                         
           26        0.8100         3/2 -                         
           27        0.8130         7/2 -                         
           28        0.8390         5/2 -                         
      LEVELS ABOVE 0.85 MEV WERE ASSUMED TO BE OVERLAPPING.       
                                                                  
  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/19/ AND NORMALIZED TO 1 MILLI-BARN AT 14 MEV.       
                                                                  
    THE GAMMA-RAY STRENGTH FUNCTION (2.23E-02) WAS ADJUSTED TO    
    REPRODUCE THE CAPTURE CROSS SECTION OF 560 MILLI-BARNS AT 100 
    KEV MEASURED BY SHORIN ET AL./20/ AND BY NAKAJIMA ET AL.      
    /21/                                                          
                                                                  
  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 = 32  (N,N'D) 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 (= 175.4) WAS ESTIMATED BY THE       
    FORMULA DERIVED FROM KIKUCHI-KAWAI'S FORMALISM/22/ 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+/23/)    
      (N,P)          5.40  MB (RECOMMENDED BY FORREST/24/)        
      (N,ALPHA)      1.49  MB (SYSTEMATICS OF FORREST/24/)        
                                                                  
    THE (N,ALPHA) CROSS SECTION BELOW 303.7 EV WAS CALCULATED     
    FROM RESONANCE PARAMETERS, BY ASSUMING A MEAN ALPHA WIDTH OF  
    2.0E-10 EV SO AS TO REPRODUCE THE THERMAL CROSS SECTION/7/.   
    THE CROSS SECTION WAS AVERAGED IN SUITABLE ENERGY INTERVALS.  
    ABOVE 303.7 EV, THE CROSS SECTION WAS CONNECTED SMOOTHLY TO   
    THE PEGASUS CALCULATION.                                      
                                                                  
  MT = 251  MU-BAR                                                
    CALCULATED WITH CASTHY/8/.                                    
                                                                  
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.  FOR OTHER REACTIONS, ISOTROPIC DISTRI- 
  BUTIONS 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  = 38.0                 R0 = 7.439    A0 = 0.47         
        WS = 8.0                  RS = 7.439    AS = 0.52         
        VSO= 7.0                  RSO= 7.439    ASO= 0.47         
  THE FORM OF SURFACE ABSORPTION PART IS DER. WOODS-SAXON TYPE.   
                                                                  
TABLE 2  LEVEL DENSITY PARAMETERS                                 
                                                                  
 NUCLIDE  SYST A(1/MEV)  T(MEV)    C(1/MEV)  EX(MEV)   PAIRING    
 ---------------------------------------------------------------  
 62-SM-153     2.572E+01 5.160E-01 2.101E+01 6.405E+00 1.220E+00  
 62-SM-154     2.190E+01 5.600E-01 1.960E+00 7.188E+00 2.140E+00  
 62-SM-155     2.402E+01 5.080E-01 8.478E+00 5.767E+00 1.220E+00  
 62-SM-156  *  2.260E+01 5.145E-01 1.309E+00 6.251E+00 1.950E+00  
                                                                  
 63-EU-154     2.267E+01 4.320E-01 1.644E+01 2.784E+00 0.0        
 63-EU-155     2.083E+01 5.200E-01 5.190E+00 4.837E+00 9.200E-01  
 63-EU-156     2.084E+01 4.030E-01 6.286E+00 1.992E+00 0.0        
 63-EU-157     1.975E+01 5.400E-01 6.628E+00 4.704E+00 7.300E-01  
                                                                  
 64-GD-155     2.500E+01 5.100E-01 2.181E+01 5.822E+00 9.700E-01  
 64-GD-156     2.254E+01 5.200E-01 1.630E+00 6.286E+00 1.890E+00  
 64-GD-157     2.278E+01 5.210E-01 1.077E+01 5.454E+00 9.700E-01  
 64-GD-158     2.155E+01 5.420E-01 2.479E+00 6.260E+00 1.700E+00  
 ---------------------------------------------------------------  
  SYST:  * = LDP'S WERE DETERMINED FROM SYSTEMATICS.              
                                                                  
 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 8.107 FOR GD-157 AND 6.845 FOR GD-158.             
                                                                  
REFERENCES                                                        
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    6, 135 (1968).                                                
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    (1973).                                                       
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    (1971).                                                       
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    (1965).                                                       
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17) GRUPPELAAR, H.: ECN-13 (1977).                                
18) MATSUMOTO, J.: PRIVATE COMMUNICATION (1981).                  
19) BENZI, V. AND REFFO, G.: CCDN-NW/10 (1969).                   
20) SHORIN, V.S., ET AL.: SOV. J. MUCL. PHYS., 19, 2 (1974).      
21) NAKAJIMA, Y., ET AL.: ANN. NUCL. ENERGY, 16, 589 (1989).      
22) KIKUCHI, K. AND KAWAI, M.: "NUCLEAR MATTER AND NUCLEAR        
    REACTIONS", NORTH HOLLAND (1968).                             
23) WEN DEN LU AND FINK, R.W.: PHYS. REV., C4, 1173 (1971).       
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