93-Np-238

 93-NP-238 JAERI      EVAL-MAR93 T.NAKAGAWA                       
                      DIST-MAR02 REV2-FEB02            20020222   
----JENDL-3.3         MATERIAL 9349                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
   ===========================================================    
   JENDL-3.2 data were automatically transformed to JENDL-3.3.    
    Interpolation of spectra: 22 (unit base interpolation)        
    (3,251) deleted, T-matrix of (4,2) deleted, and others.       
   ===========================================================    
                                                                  
HISTORY                                                           
93-03  NEW EVALUATION WAS MADE FOR JENDL-3.2.                     
                                                                  
MF=1  GENERAL INFORMATION                                         
  MT=451  DESCRIPTIVE DATA AND DICTIONARY                         
  MT=452  TOTAL NUMBER OF NEUTRONS PER FISSION                    
      SUM OF NU-P (MT=456) AND NU-D (MT=455).                     
  MT=455  DELAYED NEUTRON DATA                                    
      DETERMINED FROM SYSTEMATICS BY TUTTLE/1/, BENEDETTI/2/ AND  
      WALDO ET AL./3/  DECAY CONSTANTS WERE TAKEN FROM THE EVALU- 
      ATION BY BRADY AND ENGLAND/4/.                              
  MT=456  NUMBER OF PROMPT NEUTRONS                               
      BASED ON THE DATA BY SOLONKIN ET AL./5/ AND HOWERTON'S      
      SYSTEMATICS/6/.  A CONSTANT TERM IS AN AVERAGE OF THESE     
      TWO.                                                        
                                                                  
MF=2  RESONANCE PARAMETERS                                        
  MT=151  NO RESONANCE PARAMETERS ARE GIVEN.                      
                                                                  
      THERMAL CROSS SECTIONS AND CALCULATED RES. INTEGRAL (BARNS) 
                     0.0253 EV      RESONANCE INTEGRAL            
        TOTAL        2532.5                -                      
        ELASTIC        12.41               -                      
        FISSION      2070.                940                     
        CAPTURE       450.                201                     
                                                                  
MF=3  NEUTRON CROSS SECTIONS                                      
  MT= 1    TOTAL CROSS SECTION                                    
      CALCULATED WITH OPTICAL MODEL CODE CASTHY/7/.  PARAMETERS   
      ARE LISTED IN TABLE 1.                                      
                                                                  
  MT= 2    ELASTIC SCATTERING CROSS SECTION                       
      TOTAL - (SUM OF PARTIAL CROSS SECTIONS)                     
                                                                  
  MT= 16, 17  (N,2N) AND (N,3N) CROSS SECTIONS                    
      CALCULATED FROM A FORMULA GIVEN BY SAGEV AND CANER/8/.      
      THE REACTION CROSS SECTIONS CALCULATED WITH CASTHY WAS      
      ADOPTED AS THE NON-ELASTIC SCATTERING CROSS SECTION.        
                                                                  
  MT= 18   FISSION CROSS SECTION                                  
      CROSS SECTION OF 2070 BARNS MEASURED BY SPENCER AND BAUMANN 
      AT 0.0253 EV/9/ WAS ADOPTED AND 1/V FORM ASSUMED BELOW 20   
      KEV.  ABOVE 6.6 MEV, A SIMPLE FORMULA BY BYCHKOV ET AL./8/  
      WAS USED.  BELOW THIS, EXPERIMENTAL DATA OF BRITT AND       
      WILHELMY/10/ AND SYSTEMATICS/11/ WERE CONSIDERED.  THE      
      CROSS-SECTION CURVE WAS SMOOTHLY CONNECTED AT 20 KEV TO THE 
      ABOVE-MENTIONED DATA.                                       
                                                                  
  MT= 4, 51-79, 91  INELASTIC SCATTERING CROSS SECTION            
      CALCULATED WITH CASTHY (OPTICAL AND STATISTICAL MODEL).     
      PARAMETERS USED ARE LISTED IN TABLES 1, 2 AND 3.  THE LEVEL 
      SCHEME WAS TAKEN FROM EVALUATION BY SHURSHIKOV/12,13/.      
                                                                  
  MT= 102  CAPTURE CROSS SECTION                                  
      CALCULATED WITH CASTHY.  AVERAGE CAPTURE WIDTH AND LEVEL    
      SPACING WAS ASSUMED TO BE 0.035EV AND 0.294EV, RESPECTIVELY.
      DIRECT AND SEMI-DIRECT CAPTURE WAS CALCULATED FROM A SIMPLE 
      FORMULA OF BENZI AND REFFO/14/.                             
                                                                  
  MT= 251  MU-L                                                   
      CALCULATED WITH CASTHY                                      
                                                                  
MF=4  ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS                 
  MT= 2, 51-79, 91                                                
      CALCULATED WITH CASTHY                                      
                                                                  
  MT=16, 17, 18                                                   
      ASSUMED TO BE ISOTROPIC IN THE LABORATORY SYSTEM.           
                                                                  
MF=5  ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS                  
  MT=16, 17, 91                                                   
      EVAPORATION SPECTRA OBTAINED FROM THE LEVEL DENSITY         
      PARAMETERS WERE GIVEN.                                      
  MT=18                                                           
      EVAPORATION SPECTRA.  TEMPERATURE WAS DETERMINED FROM       
      SYSTEMATICS BY SMITH ET AL./15/                             
                                                                  
    TABLE 1   OPTICAL POTENTIAL PARAMETERS                        
              DETERMINED BY MURATA/16/ EXCEPT A CONSTANT TERM OF V
              THAT WAS SELECTED SO AS TO REPRODUCE S0 OF 1.0E-4.  
    ------------------------------------------------------------- 
         V = 40.5 - 0.05*E (MEV)                                  
        WS =  6.5 + 0.15*E (MEV): DERRIVATIVE WOOD-SAXON TYPE     
       VSO =  7.0          (MEV)                                  
        R0 = RSO = 1.32,  RS = 1.38  (FM)                         
         A = B = ASO = 0.47          (FM)                         
    ------------------------------------------------------------- 
                                                                  
    TABLE 2  LEVEL SCHEME OF NP-238 /12,13/                       
    ------------------------------------------------------------- 
        NO.  ENERGY(MEV)  SPIN-PARITY                             
    ------------------------------------------------------------- 
        G.S   0.0            2 +                                  
         1    0.02643        3 +                                  
         2    0.06222        4 +                                  
         3    0.08665        3 +                                  
         4    0.10626        5 +                                  
         5    0.12176        4 +                                  
         6    0.13601        3 -                                  
         7    0.16577        5 +                                  
         8    0.17915        4 -                                  
         9    0.18286        2 -                                  
        10    0.21548        3 -                                  
        11    0.22120        6 +                                  
        12    0.23280        5 -                                  
        13    0.25870        4 -                                  
        14    0.27558        5 +                                  
        15    0.2860         1 -                                  
        16    0.2983         6 -                                  
        17    0.30091        6 -                                  
        18    0.3286         6 +                                  
        19    0.3325         1 +                                  
        20    0.34238        5 -                                  
        21    0.3501         3 -                                  
        22    0.36841        2 -                                  
        23    0.3741         2 +                                  
        24    0.4085         6 -                                  
        25    0.4313         4 +                                  
        26    0.4404         4 -                                  
        27    0.4563         5 +                                  
        28    0.4626         6 +                                  
        29    0.5242         6 +                                  
    ------------------------------------------------------------- 
          LEVELS ABOVE 0.528 MEV WERE ASSUMED TO BE OVERLAPPING.  
                                                                  
    TABLE 3  LEVEL DENSITY PARAMETERS FOR GILBERT AND CAMERON     
             FORMULA, BASED ON THE EXCITED LEVELS GIVEN IN ENSDF  
             AND RESONANCE LEVEL SPACINGS /17/.                   
                                                                  
    ------------------------------------------------------------- 
                              PAIRING    SPIN-CUTOFF F.           
             A(1/MEV) T(MEV) ENERGY(MEV)   (MEV**0.5)    EX(MEV)  
    ------------------------------------------------------------- 
      NP-236   28.0    0.35    0.0          29.50        2.2579   
      NP-237   29.6    0.39    0.49         30.42        3.7161   
      NP-238   30.0    0.344   0.0          30.71        2.4075   
      NP-239   30.38   0.376   0.43         31.00        3.4944   
    ------------------------------------------------------------- 
        * TAKEN FROM GILBERT AND CAMERON/18/                      
                                                                  
REFERENCES                                                        
 1) R.J.TUTTLE: INDC(NDS)-107/G+SPECIAL, P.29 (1979).             
 2) G.BENEDETTI, ET AL.: NUCL. SCI. ENG., 80, 379 (1982).         
 3) R.WALDO ET AL.: PHYS. REV., C23, 1113 (1981).                 
 4) M.C.BRADY AND T.R.ENGLAND: NUCL. SCI. ENG., 103, 129 (1989).  
 5) A.A.SOLONKIN ET AL.: ATOM. ENERGY, 64, 497 (1988).            
 6) R.J.HOWERTON: NUCL. SCI. ENG., 62, 438 (1977).                
 7) S.IGARASI AND T.FUKAHORI: JAERI 1321 (1991).                  
 8) V.M.BYCHKOV ET AL.: INDC(CCP)-184/L (1982).                   
 9) J.D.SPENCER AND N.P.BAUMANN: TRANS. AMER. NUCL. SOC., 12, 284 
    (1969).  DATA WERE TAKEN FROM EXFOR 12475.                    
10) H.C.BRITT AND J.B.WILHELMY: NUCL. SCI. ENG., 72, 222 (1979).  
11) J.W.BEHRENS AND R.J.HOWERTON: NUCL. SCI. ENG., 65, 464 (1978).
12) E.N.SHURSHIKOV: NUCLEAR DATA SHEETS, 53, 601 (1988).          
13) ENSDF: EVALUATED NUCLEAR STRUCTURE DATA FILE, BNL/NNDC, AS OF 
    JAN. 1993.                                                    
14) V.BENZI AND G.REFFO: CCDN-NW/10 (1969).                       
15) A.B.SMITH ET AL.: ANL/NDM-50 (1979).                          
16) H.MATSUNOBU ET AL.: PROC. IN. CONF. ON NUCLEAR CROSS SECTIONS 
    FOR TECHNOL., KNOXVILLE, 1979, P.715 (1980).                  
17) S.F.MUGHABGHAB: NEUTRON CROSS SECTIONS, VOL.1, PART A,        
    ACADEMIC PRESS (1984).                                        
18) A.GILBERT AND A.G.W.CAMERON: CAN. J. PHYS., 43, 1446 (1965).