93-Np-236

 93-NP-236 JAERI      EVAL-MAR93 T.NAKAGAWA                       
                      DIST-MAR94                                  
----JENDL-3.2         MATERIAL 9343                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
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 FOR NP-238 BY BRADY AND ENGLAND/4/.                   
  MT=456  NUMBER OF PROMPT NEUTRONS                               
      BASED ON THE DATA BY LINDNER AND SEEGMILLER /5/ AND         
      HOWERTON'S SYSTEMATICS/6/.                                  
                                                                  
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        3483.                 -                      
        ELASTIC        12.27               -                      
        FISSION      2770.               1030                     
        CAPTURE       701.                259                     
                                                                  
MF=3  NEUTRON CROSS SECTIONS                                      
  BELOW 20 KEV                                                    
  ============                                                    
  MT= 1    TOTAL CROSS SECTION                                    
      SUM OF PARTIAL CROSS SECTIONS.                              
                                                                  
  MT= 2    ELASTIC SCATTERING CROSS SECTION                       
      CALCULATED WITH OPTICAL MODEL CODE CASTHY/7/.               
                                                                  
  MT= 18   FISSION CROSS SECTION                                  
      BASED ON THE DATA MEASURED BY VAL'SKIY ET AL./8/            
                                                                  
  MT= 102  CAPTURE CROSS SECTION                                  
      CAPTURE-TO-FISSION RATIO WAS ASSUMED TO BE 0.253 THAT WAS   
      OBTAINED FROM THE CAPTURE CROSS SECTION CALCULATED AT 20 KEV
      AND THE FISSION CROSS SECTION.                              
                                                                  
  ABOVE 20 KEV                                                    
  ============                                                    
  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/9/.      
      THE REACTION CROSS SECTIONS CALCULATED WITH CASTHY WAS      
      ADOPTED AS THE NON-ELASTIC SCATTERING CROSS SECTION.        
                                                                  
  MT= 18   FISSION CROSS SECTION                                  
      ABOVE 5 MEV, A SIMPLE FORMULA BY BYCHKOV ET AL./9/ WAS USED.
      EXPERIMENTAL DATA OF BRITT AND WILHELMY/10/ AND SYSTEMA-    
      TICS/11/ WERE CONSIDERED.  THE CROSS-SECTION CURVE WAS      
      SMOOTHLY CONNECTED AT 20 KEV TO THE DATA OF VAL'SKIY ET     
      AL./8/                                                      
                                                                  
  MT= 4, 51-54, 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 SCHMORAK/12,13/.        
                                                                  
  MT= 102  CAPTURE CROSS SECTION                                  
      CALCULATED WITH CASTHY.  AVERAGE CAPTURE WIDTH AND LEVEL    
      SPACING WAS ASSUMED TO BE 0.035 EV AND 0.11EV, 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, 51-54, 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-236 /12,13/                       
    ------------------------------------------------------------- 
        NO.  ENERGY(MEV)  SPIN-PARITY                             
    ------------------------------------------------------------- 
        G.S   0.0            6 -                                  
         1    0.060          1 +                                  
         2    0.231          3 -                                  
         3    0.273          4 -                                  
         4    0.324          5 -                                  
    ------------------------------------------------------------- 
          LEVELS ABOVE 0.370 MEV WERE ASSUMED TO BE OVERLAPPING.  
                                                                  
    TABLE 3  LEVEL DENSITY PARAMETERS FOR GILBERT AND CAMERON     
             FORMULA, BASED ON THE EXCITED LEVELS GIVEN IN ENSDF. 
                                                                  
    ------------------------------------------------------------- 
                              PAIRING    SPIN-CUTOFF F.           
             A(1/MEV) T(MEV) ENERGY(MEV)   (MEV**0.5)    EX(MEV)  
    ------------------------------------------------------------- 
      NP-234*  27.16           0.0          17.57        3.1410   
      NP-235   31.4    0.35    0.57         31.16        3.2900   
      NP-236   28.0    0.35    0.0          29.50        2.2579   
      NP-237   29.6    0.39    0.49         30.42        3.7161   
    ------------------------------------------------------------- 
        * TAKEN FROM GILBERT AND CAMERON/17/                      
                                                                  
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) M.LINDNER AND D.W.SEEGMILLER: RADIOCHIMICA ACTA, 49, 1(1990). 
 6) R.J.HOWERTON: NUCL. SCI. ENG., 62, 438 (1977).                
 7) S.IGARASI AND T.FUKAHORI: JAERI 1321 (1991).                  
 8) G.V.VAL'SKIY ET AL.: PROC. 1ST INT. CONF. ON NEUTRON PHYSICS, 
    KIEV 1987, VOL. 3, P.99 (1987).  DATA WERE TAKEN FROM EXFOR   
    40995                                                         
 9) V.M.BYCHKOV ET AL.: INDC(CCP)-184/L (1982).                   
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) M.R.SCHMORAK: NUCLEAR DATA SHEETS, 63, 139 (1991).            
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) A.GILBERT AND A.G.W.CAMERON: CAN. J. PHYS., 43, 1446 (1965).