64-Gd-154

 64-GD-154 JNDC       EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.        
                      DIST-NOV90                                  
----JENDL-3.2         MATERIAL 6431                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
HISTORY                                                           
90-03 NEW EVALUATION FOR JENDL-3 WAS COMPLETED BY JNDC FPND       
      W.G./1/                                                     
                                                                  
MF = 1  GENERAL INFORMATION                                       
  MT=451 COMMENTS AND DICTIONARY                                  
                                                                  
MF = 2  RESONANCE PARAMETERS                                      
  MT=151 RESOLVED AND UNRESOLVED RESONANCE PARAMETERS             
  RESOLVED RESONANCE REGION (MLBW FORMULA) : BELOW 2.76 KEV       
       RESONANCE PARAMETERS BELOW 486 EV WERE EVALUATED ON THE    
    BASIS OF MUGHABGHAB/2/.                                       
       ABOVE 486 EV, PARAMETERS WERE ADOPTED FROM MACKLIN/3/.  FOR
    THE RESONANCES ONLY WHOSE CAPTURE AREA WAS MEASURED, NEUTRON  
    WIDTHS WERE DETERMINED FROM THE CAPTURE AREA AND AN AVERAGE   
    RADIATION WIDTH OF 0.088 EV/2/.  THE TOTAL SPIN J AND ORBITAL 
    ANGULAR MOMENTUM L WERE ASSIGNED BY CONSIDERING THE MAGNITUDE 
    OF THE CAPTURE AREA OF EACH RESONANCE.                        
       A NEGATIVE RESONANCE WAS ADDED SO AS TO REPRODUCE THE      
    THERMAL CAPTURE CROSS SECTION OF 85+-12 BARNS/2/.             
       SCATTERING RADIUS OF 8.0 FM WAS ESTIMATED FROM AN OPTICAL  
    MODEL CALCULATION SHOWN IN FIG. 2 OF REF./2/.                 
                                                                  
  UNRESOLVED RESONANCE REGION : 2.76 KEV - 100 KEV                
    THE NEUTRON STRENGTH FUNCTION S0 WAS BASED ON THE COMPILATION 
    OF MUGHABGHAB, AND S1 AND S2 WERE CALCULATED WITH OPTICAL     
    MODEL CODE CASTHY/4/.  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 = 2.000E-4, S1 = 1.100E-4, S2 = 2.400E-4, SG = 45.9E-4,    
    GG = 0.088 EV, R  = 6.802 FM.                                 
                                                                  
  CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)   
                     2200 M/S               RES. INTEG.           
      TOTAL          92.35                     -                  
      ELASTIC         7.356                    -                  
      CAPTURE        84.99                    215                 
                                                                  
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/5/ STANDING ON A PREEQUILIBRIUM AND MULTI-STEP     
  EVAPORATION MODEL.  THE OMP'S FOR NEUTRON GIVEN IN TABLE 1 WERE 
  ADOPTED FROM IIJIMA AND KAWAI/6/ AND WS WAS CHANGED.  THE OMP'S 
  FOR CHARGED PARTICLES ARE AS FOLLOWS:                           
     PROTON   = PEREY/7/                                          
     ALPHA    = HUIZENGA AND IGO/8/                               
     DEUTERON = LOHR AND HAEBERLI/9/                              
     HELIUM-3 AND TRITON = BECCHETTI AND GREENLEES/10/            
  PARAMETERS FOR THE COMPOSITE LEVEL DENSITY FORMULA OF GILBERT   
  AND CAMERON/11/ WERE EVALUATED BY IIJIMA ET AL./12/  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
  /13/.                                                           
                                                                  
  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 BASED ON EVALUATED NUCLEAR      
    STRUCTURE DATA FILE (1987 VERSION)/14/ AND NUCLEAR DATA       
    SHEETS/15/.                                                   
                                                                  
           NO.      ENERGY(MEV)    SPIN-PARITY                    
           GR.       0.0             0  +                         
            1        0.1231          2  +                         
            2        0.3710          4  +                         
            3        0.6807          0  +                         
            4        0.7177          6  +                         
            5        0.8155          2  +                         
            6        0.9963          2  +                         
            7        1.0476          4  +                         
            8        1.1278          3  +                         
            9        1.1445          8  +                         
           10        1.2413          1  -                         
           11        1.2516          3  -                         
           12        1.2638          4  +                         
           13        1.2951          0  +                         
           14        1.3650          5  -                         
           15        1.3659          6  +                         
           16        1.3975          2  -                         
           17        1.4145          1  -                         
           18        1.4184          2  +                         
           19        1.4323          5  +                         
           20        1.5313          2  +                         
           21        1.5596          4  -                         
           22        1.6066          6  +                         
           23        1.6172          3  -                         
           24        1.6458          4  +                         
           25        1.6609          3  +                         
           26        1.6983          4  +                         
           27        1.7196          2  -                         
           28        1.7567          8  +                         
      LEVELS ABOVE 1.77 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/16/ AND NORMALIZED TO 1 MILLI-BARN AT 14 MEV.       
                                                                  
    THE GAMMA-RAY STRENGTH FUNCTION (42.8E-4) WAS ADJUSTED TO     
    REPRODUCE THE CAPTURE CROSS SECTION OF 680 MILLI-BARNS AT 50  
    KEV MEASURED BY BEER AND MACKLIN/17/                          
                                                                  
  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 (= 106.1) WAS ESTIMATED BY THE       
    FORMULA DERIVED FROM KIKUCHI-KAWAI'S FORMALISM/18/ AND LEVEL  
    DENSITY PARAMETERS.                                           
                                                                  
    FINALLY, THE (N,P) AND (N,ALPHA) CROSS SECTIONS WERE          
    NORMALIZED TO THE FOLLOWING VALUES AT 14.5 MEV:               
      (N,P)          8.23  MB (SYSTEMATICS OF FORREST/19/)        
      (N,ALPHA)      2.91  MB (SYSTEMATICS OF FORREST)            
                                                                  
  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       A(1/MEV)  T(MEV)    C(1/MEV)  EX(MEV)   PAIRING    
 ---------------------------------------------------------------  
 62-SM-150     2.362E+01 5.230E-01 1.520E+00 6.973E+00 2.210E+00  
 62-SM-151     2.687E+01 5.000E-01 2.313E+01 6.327E+00 1.220E+00  
 62-SM-152     2.375E+01 5.470E-01 2.365E+00 7.669E+00 2.330E+00  
 62-SM-153     2.572E+01 5.160E-01 2.101E+01 6.405E+00 1.220E+00  
                                                                  
 63-EU-151     2.511E+01 4.680E-01 8.573E+00 4.962E+00 9.900E-01  
 63-EU-152     2.484E+01 4.850E-01 8.700E+01 4.264E+00 0.0        
 63-EU-153     2.195E+01 5.750E-01 1.698E+01 6.504E+00 1.110E+00  
 63-EU-154     2.267E+01 4.320E-01 1.644E+01 2.784E+00 0.0        
                                                                  
 64-GD-152     2.470E+01 4.810E-01 1.302E+00 6.106E+00 1.960E+00  
 64-GD-153     2.484E+01 5.130E-01 2.189E+01 5.847E+00 9.700E-01  
 64-GD-154     2.349E+01 5.270E-01 2.018E+00 6.893E+00 2.080E+00  
 64-GD-155     2.500E+01 5.100E-01 2.181E+01 5.822E+00 9.700E-01  
 ---------------------------------------------------------------  
                                                                  
 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 9.839 FOR GD-154 AND 7.017 FOR GD-155.             
                                                                  
REFERENCES                                                        
 1) KAWAI, M. ET AL.: PROC. INT. CONF. ON NUCLEAR DATA FOR SCIENCE
    AND TECHNOLOGY, MITO, P. 569 (1988).                          
 2) MUGHABGHAB, S.F.: "NEUTRON CROSS SECTIONS, VOL. I, PART B",   
    ACADEMIC PRESS (1984).                                        
 3) MACKLIN, R.L.: NUCL. SCI. ENG., 95. 304 (1987).               
 4) IGARASI, S.: J. NUCL. SCI. TECHNOL., 12, 67 (1975).           
 5) IIJIMA, S. ET AL.: JAERI-M 87-025, P. 337 (1987).             
 6) IIJIMA, S. AND KAWAI, M.: J. NUCL. SCI. TECHNOL., 20, 77      
    (1983).                                                       
 7) PEREY, F.G: PHYS. REV. 131, 745 (1963).                       
 8) HUIZENGA, J.R. AND IGO, G.: NUCL. PHYS. 29, 462 (1962).       
 9) LOHR, J.M. AND HAEBERLI, W.: NUCL. PHYS. A232, 381 (1974).    
10) BECCHETTI, F.D., JR. AND GREENLEES, G.W.: POLARIZATION        
    PHENOMENA IN NUCLEAR REACTIONS ((EDS) H.H. BARSHALL AND       
    W. HAEBERLI), P. 682, THE UNIVERSITY OF WISCONSIN PRESS.      
    (1971).                                                       
11) GILBERT, A. AND CAMERON, A.G.W.: CAN. J. PHYS., 43, 1446      
    (1965).                                                       
12) IIJIMA, S., ET AL.: J. NUCL. SCI. TECHNOL. 21, 10 (1984).     
13) GRUPPELAAR, H.: ECN-13 (1977).                                
14) ENSDF: EVALUATED NUCLEAR STRUCTURE DATA FILE (JUNE 1987).     
15) NUCLEAR DATA SHEETS, 26, 281 (1979).                          
16) BENZI, V. AND REFFO, G.: CCDN-NW/10 (1969).                   
17) BEER, H. AND MACKLIN, R.: ASTROPHYSICAL J., 331, 1047(1988).  
18) KIKUCHI, K. AND KAWAI, M.: "NUCLEAR MATTER AND NUCLEAR        
    REACTIONS", NORTH HOLLAND (1968).                             
19) FORREST, R.A.: AERE-R 12419 (1986).