64-Gd-158

 64-GD-158 JNDC       EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.        
                      DIST-NOV90                                  
----JENDL-3.2         MATERIAL 6443                               
-----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 6.58 KEV) 
    RESONANCE PARAMETERS WERE TAKEN FROM JENDL-2 WHOSE EVALUATION 
    WAS MADE AS FOLLOWS:  PARAMETERS WERE MAINLY TAKEN FROM THE   
    EXPERIMENTAL DATA OF RAHN ET AL./3/.  THE AVERAGE RADIATIVE   
    CAPTURE WIDTH OF 0.088 EV WAS ASSUMED.  A NEGATIVE RESONANCE  
    WAS ADDED SO AS TO REPRODUCE THE THERMAL CAPTURE CROSS SECTION
    GIVEN BY MUGHABGHAB AND GARBER/4/.  SCATTERING RADIUS OF 6.5  
    FM WAS ADOPTED FROM REF./4/.                                  
                                                                  
  UNRESOLVED RESONANCE REGION : 6.58 KEV - 100 KEV                
    THE NEUTRON STRENGTH FUNCTIONS, S0 AND S2 WERE BASED ON THE   
    COMPILATION OF MUGHABGHAB/5/, AND S1 WAS CALCULATED WITH      
    OPTICAL MODEL CODE CASTHY/6/.  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 = 1.500E-4, S1 = 1.100E-4, S2 = 1.900E-4, SG = 9.30E-4,    
    GG = 0.105 EV, R  = 7.119 FM.                                 
                                                                  
  CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)   
                     2200 M/S               RES. INTEG.           
      TOTAL           6.354                    -                  
      ELASTIC         3.858                    -                  
      CAPTURE         2.496                    64.0               
                                                                  
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/7/ STANDING ON A PREEQUILIBRIUM AND MULTI-STEP     
  EVAPORATION MODEL.  THE OMP'S FOR NEUTRON GIVEN IN TABLE 1 WERE 
  ADOPTED FROM IIJIMA AND KAWAI/8/, AND WS WAS CHANGED.  THE OMP'S
  FOR CHARGED PARTICLES ARE AS FOLLOWS:                           
     PROTON   = PEREY/9/                                          
     ALPHA    = HUIZENGA AND IGO/10/                              
     DEUTERON = LOHR AND HAEBERLI/11/                             
     HELIUM-3 AND TRITON = BECCHETTI AND GREENLEES/12/            
  PARAMETERS FOR THE COMPOSITE LEVEL DENSITY FORMULA OF GILBERT   
  AND CAMERON/13/ WERE EVALUATED BY IIJIMA ET AL./14/  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
  /15/.                                                           
                                                                  
  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./16/.           
                                                                  
           NO.      ENERGY(MEV)    SPIN-PARITY                    
           GR.       0.0             0  +                         
            1        0.0795          2  +                         
            2        0.2614          4  +                         
            3        0.5390          6  +                         
            4        0.9771          1  -                         
            5        1.0237          2  -                         
            6        1.0416          3  -                         
            7        1.1590          4  -                         
            8        1.1760          5  -                         
            9        1.1870          2  +                         
           10        1.1960          0  +                         
           11        1.2600          2  +                         
           12        1.2640          1  -                         
           13        1.2650          3  +                         
           14        1.3580          4  +                         
           15        1.3720          6  -                         
           16        1.3810          4  +                         
           17        1.4030          3  -                         
           18        1.4070          4  +                         
           19        1.4520          0  +                         
           20        1.5170          2  +                         
           21        1.6360          4  -                         
           22        1.6670          4  +                         
           23        1.7430          0  +                         
           24        1.7920          2  +                         
           25        1.7940          2  -                         
      LEVELS ABOVE 1.85 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/17/ AND NORMALIZED TO 1 MILLI-BARN AT 14 MEV.       
                                                                  
    THE GAMMA-RAY STRENGTH FUNCTION (8.02E-4) WAS ADJUSTED TO     
    REPRODUCE THE CAPTURE CROSS SECTION OF 250 MILLI-BARNS AT 50  
    KEV MEASURED BY KONONOV ET AL./18/ AND SHORIN ET AL./19/      
                                                                  
  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 (= 145.5) WAS ESTIMATED BY THE       
    FORMULA DERIVED FROM KIKUCHI-KAWAI'S FORMALISM/20/ AND LEVEL  
    DENSITY PARAMETERS.                                           
                                                                  
    FINALLY, THE (N,2N) AND (N,ALPHA) CROSS SECTIONS WERE         
    NORMALIZED TO THE FOLLOWING VALUES AT 14.5 MEV:               
      (N,2N)      1800.00  MB (SYSTEMATICS OF WEN DEN LU+/21/)    
      (N,ALPHA)      2.30  MB (MEASURED BY LAKSHMANA+/22/)        
                                                                  
  MT = 251  MU-BAR                                                
    CALCULATED WITH CASTHY.                                       
                                                                  
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-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  
 62-SM-157  *  2.193E+01 5.121E-01 3.892E+00 5.288E+00 1.220E+00  
                                                                  
 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  
 63-EU-158  *  2.207E+01 5.096E-01 4.288E+01 4.059E+00 0.0        
                                                                  
 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  
 64-GD-159     2.308E+01 5.160E-01 1.099E+01 5.433E+00 9.700E-01  
 ---------------------------------------------------------------  
  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 6.845 FOR GD-158 AND 5.0 FOR GD-159.               
                                                                  
REFERENCES                                                        
 1) AOKI, T. ET AL.: PROC. INT. CONF. ON NUCLEAR DATA FOR BASIC   
    AND APPLIED SCIENCE, SANTA FE., VOL. 2, P.1627 (1985).        
 2) KAWAI, M. ET AL.: PROC. INT. CONF. ON NUCLEAR DATA FOR SCIENCE
    AND TECHNOLOGY, MITO, P. 569 (1988).                          
 3) RAHN, F., ET AL.: PHYS. REV., C10, 1904 (1974).               
 4) MUGHABGHAB, S.F. AND GARBER, D.I.: "NEUTRON CROSS SECTIONS,   
    VOL.1, RESONANCE PARAMETERS", BNL 325, 3RD ED., VOL. 1,       
    (1973).                                                       
 5) MUGHABGHAB, S.F.: "NEUTRON CROSS SECTIONS, VOL. I, PART B",   
    ACADEMIC PRESS (1984).                                        
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    (1983).                                                       
 9) PEREY, F.G: PHYS. REV. 131, 745 (1963).                       
10) HUIZENGA, J.R. AND IGO, G.: NUCL. PHYS. 29, 462 (1962).       
11) LOHR, J.M. AND HAEBERLI, W.: NUCL. PHYS. A232, 381 (1974).    
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    (1971).                                                       
13) GILBERT, A. AND CAMERON, A.G.W.: CAN. J. PHYS., 43, 1446      
    (1965).                                                       
14) IIJIMA, S., ET AL.: J. NUCL. SCI. TECHNOL. 21, 10 (1984).     
15) GRUPPELAAR, H.: ECN-13 (1977).                                
16) LEDERER, C.M., ET AL.: "TABLE OF ISOTOPES, 7TH ED.", WILEY-   
    INTERSCIENCE PUBLICATION (1978).                              
17) BENZI, V. AND REFFO, G.: CCDN-NW/10 (1969).                   
18) KONONOV, V.N., ET AL.: SOV. J. NUCL. PHYS., 27, 5 (1978).     
19) SHORIN, V.S., ET AL.: SOV. J. NUCL. PHYS., 19, 2 (1974).      
20) KIKUCHI, K. AND KAWAI, M.: "NUCLEAR MATTER AND NUCLEAR        
    REACTIONS", NORTH HOLLAND (1968).                             
21) WEN DEN LU AND FINK, R.W.: PHYS. REV., C4, 1173 (1971).       
22) LAKSHMANA, N., ET AL.: ANNALS OF NUCLEAR ENERGY, 8(6),283     
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