39-Y - 89

 39-Y - 89 JNDC       EVAL-MAR90 JNDC FP NUCLEAR DATA W.G.        
                      DIST-SEP90 REV2-NOV93                       
----JENDL-3.2         MATERIAL 3925                               
-----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/.                       
93-11 JENDL-3.2 WAS MADE BY JNDC FPND W.G.                        
                                                                  
     *****   MODIFIED PARTS FOR JENDL-3.2   ********************  
      (2,151)       RESOLVED RESONANCE PARAMETERS                 
     ***********************************************************  
                                                                  
                                                                  
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 48 KEV         
    RESONANCE PARAMETERS WERE TAKEN FROM JENDL-2 AFTER SLIGHT     
    MODIFICATION.                                                 
       FOR JENDL-2, RESONANCE ENERGIES WERE TAKEN FROM BOLDEMAN ET
    AL./3/ FOR THE LEVELS BELOW 47 KEV AND CAMARDA ET AL./4/ FOR  
    THOSE ABOVE 50 KEV.  FOR THE NEUTRON WIDTHS, ADOPTED WERE     
    AVERAGE VALUES OF MORGENSTERN ET AL./5/, BOLDEMAN ET AL. AND  
    CAMARDA ET AL.  THE RADIATION WIDTHS WERE DERIVED FROM CAPTURE
    AREAS MEASURED BY BOLDEMAN ET AL.                             
       AVERAGE RADIATION WIDTH = 0.123 +- 0.027 EV FOR S-WAVE RES.
                                 0.279 +- 0.127 EV FOR P-WAVE RES.
    THE SCATTERING RADIUS OF 6.7 FM WAS TAKEN FROM REF./6/.       
       FOR JENDL-3, ONLY TOTAL SPIN J AND ANGULAR MOMENTUM L OF   
    SOME RESONANCES WERE ESTIMATED WITH A RANDOM NUMBER METHOD AND
    A METHOD OF BOLLINGER AND THOMAS/7/, RESPECTIVELY.  A NEGATIVE
    RESONANCE AT -251 EV WAS ADDED SO AS TO REPRODUCE THE THERMAL 
    CAPTURE AND SCATTERING CROSS SECTIONS GIVEN BY MUGHABGHAB ET  
    AL./6/                                                        
       FOR JENDL-3.2, THE PARAMETERS FOR LEVELS MEASURED BY       
    BOLDEMAN ET AL. IN THE ENERGY RANGE UP TO 46.07 KEV WERE      
    REEVALUATED USING THEIR CAPTURE AREAS MULTIPLIED BY A FACTOR  
    OF 1.036 ACCORDING TO A CORRIGENDUM REPORTED BY ALLEN ET      
    AT./8/                                                        
                                                                  
  UNRESOLVED RESONANCE REGION : 48 KEV - 100 KEV                  
    UNRESOLVED RESONANCE PARAMETERS WERE ADOPTED FROM JENDL-2.    
    THE NEUTRON STRENGTH FUNCTIONS, S0 AND S1 WERE ADOPTED FROM   
    THE RECOMMENDATION IN REF./9/, AND WAS CALCULATED WITH        
    OPTICAL MODEL CODE CASTHY/10/.  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.
                                                                  
  TYPICAL VALUES OF THE PARAMETERS AT 70 KEV:                     
    S0 = 0.320E-4, S1 = 4.400E-4, S2 = 0.360E-4, SG = 0.626E-4,   
    GG = 0.132 EV, R  = 7.235 FM.                                 
                                                                  
  CALCULATED 2200-M/S CROSS SECTIONS AND RES. INTEGRALS (BARNS)   
                     2200 M/S               RES. INTEG.           
      TOTAL           8.9900                   -                  
      ELASTIC         7.7127                   -                  
      CAPTURE         1.2773                    0.870             
                                                                  
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/11/ STANDING ON A PREEQUILIBRIUM AND MULTI-STEP    
  EVAPORATION MODEL.  THE OMP'S FOR NEUTRON GIVEN IN TABLE 1 WERE 
  DETERMINED BY IIJIMA AND KAWAI/12/ TO REPRODUCE A SYSTEMATIC    
  TREND OF THE TOTAL CROSS SECTION.  THE OMP'S FOR CHARGED        
  PARTICLES ARE AS FOLLOWS:                                       
     PROTON   = PEREY/13/                                         
     ALPHA    = HUIZENGA AND IGO/14/                              
     DEUTERON = LOHR AND HAEBERLI/15/                             
     HELIUM-3 AND TRITON = BECCHETTI AND GREENLEES/16/            
  PARAMETERS FOR THE COMPOSITE LEVEL DENSITY FORMULA OF GILBERT   
  AND CAMERON/17/ WERE EVALUATED BY IIJIMA ET AL./18/  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
  /19/.                                                           
                                                                  
  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./20/.           
                                                                  
           NO.      ENERGY(MEV)    SPIN-PARITY                    
           GR.       0.0            1/2 -                         
            1        0.9091         9/2 +                         
            2        1.5074         3/2 -                         
            3        1.7445         5/2 -                         
            4        2.2210         5/2 +                         
            5        2.5299         7/2 +                         
            6        2.5664        11/2 +                         
            7        2.6222         9/2 +                         
            8        2.8710         7/2 +                         
            9        2.8820         3/2 -                         
           10        3.0680         3/2 -                         
           11        3.1060         5/2 -                         
           12        3.1380         5/2 -                         
      LEVELS ABOVE 3.502 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/21/ AND NORMALIZED TO 1 MILLI-BARN AT 14 MEV.       
                                                                  
    THE GAMMA-RAY STRENGTH FUNCTION (5.95E-05) WAS ADJUSTED TO    
    REPRODUCE THE CAPTURE CROSS SECTION OF 13 MILLI-BARNS AT 70   
    KEV MEASURED BY MUSGROVE ET AL./22,8/                         
                                                                  
  MT = 16  (N,2N) 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 =106  (N,HE3) 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 (= 299.5) WAS ESTIMATED BY THE       
    FORMULA DERIVED FROM KIKUCHI-KAWAI'S FORMALISM/23/ 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)       980.00  MB (RECOMMENDED BY  BYCHKOV+/24/)      
      (N,P)         25.00  MB (RECOMMENDED BY  FORREST/25/)       
      (N,ALPHA)      5.50  MB (RECOMMENDED BY  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  = 46.0-0.25E           R0 = 5.893    A0 = 0.62         
        WS = 7.0                  RS = 6.393    AS = 0.35         
        VSO= 7.0                  RSO= 5.893    ASO= 0.62         
  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    
 ---------------------------------------------------------------  
 37-RB- 85     1.190E+01 8.690E-01 2.827E+00 7.561E+00 1.460E+00  
 37-RB- 86     1.002E+01 8.500E-01 3.954E+00 4.312E+00 0.0        
 37-RB- 87     8.806E+00 9.410E-01 1.125E+00 5.465E+00 9.300E-01  
 37-RB- 88     9.801E+00 8.185E-01 2.880E+00 3.704E+00 0.0        
                                                                  
 38-SR- 86     1.120E+01 8.900E-01 5.328E-01 8.599E+00 2.700E+00  
 38-SR- 87     1.030E+01 8.610E-01 1.186E+00 5.938E+00 1.240E+00  
 38-SR- 88     9.160E+00 7.510E-01 8.288E-02 4.550E+00 2.170E+00  
 38-SR- 89     9.380E+00 8.200E-01 5.043E-01 4.642E+00 1.240E+00  
                                                                  
 39-Y - 87  *  1.388E+01 7.471E-01 2.541E+00 6.730E+00 1.460E+00  
 39-Y - 88     1.109E+01 7.450E-01 3.738E+00 3.570E+00 0.0        
 39-Y - 89     7.900E+00 8.500E-01 3.983E-01 3.440E+00 9.300E-01  
 39-Y - 90     1.027E+01 6.770E-01 1.716E+00 2.209E+00 0.0        
 ---------------------------------------------------------------  
  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 6.916 FOR Y - 89 AND 5.0 FOR Y - 90.               
                                                                  
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