24-Cr- 52

 24-Cr- 52 JAEA,ORNL  EVAL-Nov09 N.Iwamoto,L.Leal+                
                      DIST-SEP12                       20111216   
----JENDL-4.0u1       MATERIAL 2431                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
Update File Distribution                                          
Sep.14,2012 JENDL-4.0u1                                           
                                                                  
History                                                           
09-11 The resolved resonance parameters were evaluated by         
      L.Leal+.                                                    
      The data above the resolved resonance region were evaluated 
      and compiled by N.Iwamoto.                                  
10-06 MF33 and MF34 were added by N.Iwamoto.                      
11-12 MF33/MT1 and MF33/MT102 were revised by N.Iwamoto.          
                                                                  
MF= 1 General information                                         
  MT=451 Descriptive data and directory                           
                                                                  
MF= 2  Resonance parameters                                       
  MT=151 Resolved and unresolved resonance parameters             
The details of the resolved resonance parameters are given below: 
================================================================= 
EVALUATION of the RESONANCE PARAMETERS of Cr-52 in the ENERGY     
RANGE below 1.43 MeV                                              
================================================================= 
 24-Cr- 52 ORNL Resonance Evaluation Including Covariance         
                                                                  
 L. C. Leal, H. Derrien, K. Guber, G. Arbanas and D. Wiarda       
                                                                  
 Resolved resonance parameter evaluation for Cr-52 was done with  
the computer code SAMMY.[ref1] Capture and transmission           
measurements enriched Cr-52 and natural chromium were performed   
at the Oak Ridge Electron Linear Accelerator (ORELA) of the Oak   
Ridge National Laboratory. The neutron transmission and capture   
data were measured in the energy range from 10 keV to 600 keV.    
The transmission data were measured at the 80-meter flight-path,  
whereas the 40-meter flight-path was used for the capture cross   
section measurements. The determination of the resolved resonance 
parameters for the chromium isotope below 100 keV relied mainly   
on the recent ORELA measurements. The ORELA capture cross section 
data were essential in the evaluation since there are no capture  
cross section data available in the literature. In                
addition to the new ORELA measurements, existing high-resolution  
transmission data for enriched nuclides were also included in the 
evaluation. Thermal cross section data available in the EXFOR data
system were also included in the evaluation.                      
                                                                  
 Direct-semidirect (DSD) capture on Cr-52 was computed using the  
computer code CUPIDO created by F.S. Dietrich (LLNL).[ref2]  To   
obtain the optical potential for this computation, the global     
optical potential of Koning-Delaroche was manually adjusted to    
reproduce the experimentally measured scattering radius R'.       
This method was justified since low-energy phenomena are          
determined by R'.  It was found that the low-energy capture is    
dominated by electric-dipole (E1) capture of s-wave neutrons.  A  
density form of the E1 operator was used.  The spectroscopic      
factors for the capturing bound states in Cr-53 were taken from   
L.K. Peker.[ref3] The computed thermal DSD capture is about 0.11  
barns.  The uncertainty of DSD computation is inherently large,   
usually about 20-30%.                                             
                                                                  
 A set of resonance parameter describing the experimental data    
was obtained. Resonance parameter covariance matrices were also   
obtained in the SAMMY evaluation process. The Cr-52 evaluation was
done in the energy region 10-5 eV 1.43 MeV.                       
  Thermal cross section obtained in the present evaluation are    
compared to the values listed in the Atlas of Neutron Resoances   
in the following table:                                           
                                                                  
    Cross Section            ORNL                      Atlas      
                   Resonance     Res+Direct                       
       Capt        0.75+/-0.02      0.86             0.86+/-0.02  
       Total       3.82+/-0.01      3.93             3.82+/-0.03  
       Scat        3.07+/-0.07       -               2.96+/-0.02  
                                                                  
 Uncertainty in the group cross section around the thermal cross  
section due the covarinace data has been calculated for a energy  
group between the energies 0.0253 eV and 0.3 eV. The average cross
sections for this energy group are listed in the following tale:  
                                                                  
            Cross Section                Average Value            
                                                                  
                Capt                   0.72+/-0.02 (2.8%)         
                Total                  3.79+/-0.11 (2.9%)         
                Scat                   3.07+/-0.08 (2.6%)         
                                                                  
 [ref 1] N. M. Larson,"Updated Users' Guide for SAMMY," Oak Ridge 
            National Laboratory report  ORNL/TM-9179/R6 (2003)    
 [ref 2] W.E. Parker et al., Phys. Rev. C 52, 252 - 266 (1995)    
 [ref 3] Nuclear Data Sheets 43, 481 (1984), page 531             
                                                                  
      Thermal cross sections and resonance integrals at 300 K     
      ----------------------------------------------------------  
                       0.0253 eV           res. integ. (*)        
                        (barn)               (barn)               
      ----------------------------------------------------------  
       Total           3.9341e+00                                 
       Elastic         3.0776e+00                                 
       n,gamma         8.5607e-01           4.9403e-01            
      ----------------------------------------------------------  
         (*) Integrated from 0.5 eV to 10 MeV.                    
                                                                  
MF= 3 Neutron cross sections                                      
  MT=  1 Total cross section                                      
    In the energy range from 1.43 to 6.751 MeV, cross section was 
      adopted from JENDL-3.3. Above 6.751 MeV, cross section was  
      calculated with CCONE code/1/.                              
                                                                  
  MT=  2 Elastic scattering cross section                         
    Obtained by subtracting non-elastic scattering cross sections 
      from total cross section.                                   
                                                                  
  MT=  4 (n,n') cross section                                     
    Sum of partial cross sections in MT= 51-91.                   
                                                                  
  MT= 16 (n,2n) cross section                                     
    Calculated with CCONE code /1/.                               
                                                                  
  MT= 22 (n,na) cross section                                     
    Calculated with CCONE code /1/.                               
                                                                  
  MT= 28 (n,np) cross section                                     
    Calculated with CCONE code /1/.                               
                                                                  
  MT= 51, 52 (n,n') cross section                                 
    Cross sections were evaluated on the basis of experimental    
      data of Mihailescu et al./2/.                               
                                                                  
  MT= 53-91 (n,n') cross section                                  
    Calculated with CCONE code /1/.                               
                                                                  
  MT=102 Capture cross section                                    
    Calculated with CCONE code /1/.                               
                                                                  
  MT=103 (n,p) cross section                                      
    Calculated with CCONE code /1/.                               
                                                                  
  MT=104 (n,d) cross section                                      
    Calculated with CCONE code /1/.                               
                                                                  
  MT=105 (n,t) cross section                                      
    Calculated with CCONE code /1/.                               
                                                                  
  MT=106 (n,He3) cross section                                    
    Calculated with CCONE code /1/.                               
                                                                  
  MT=107 (n,a) cross section                                      
    Calculated with CCONE code /1/.                               
                                                                  
  MT=111 (n,2p) cross section                                     
    Calculated with CCONE code /1/.                               
                                                                  
  MT=112 (n,pa) cross section                                     
    Calculated with CCONE code /1/.                               
                                                                  
  MT=115 (n,pd) cross section                                     
    Calculated with CCONE code /1/.                               
                                                                  
MF= 4 Angular distributions of emitted neutrons                   
  MT=  2 Elastic scattering                                       
    Calculated with CCONE code /1/.                               
                                                                  
MF= 6 Energy-angle distributions of emitted particles             
  MT= 16 (n,2n) reaction                                          
    Calculated with CCONE code /1/.                               
                                                                  
  MT= 22 (n,na) reaction                                          
    Calculated with CCONE code /1/.                               
                                                                  
  MT= 28 (n,np) reaction                                          
    Calculated with CCONE code /1/.                               
                                                                  
  MT= 51-91 (n,n') reaction                                       
    Calculated with CCONE code /1/.                               
                                                                  
  MT=102 Capture reaction                                         
    Calculated with CCONE code /1/.                               
                                                                  
MF=32 Covariances of resonance parameters                         
  MT=151                                                          
    Covariance data were taken from the ORNL Resonance Evaluation.
      The details were explained in MF/MT=2/151.                  
                                                                  
MF=33 Covariances of neutron cross sections                       
  MT=  1 Total cross section                                      
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=  2 Elastic scattering cross section                         
    Obtained in terms of the covariance matrices of the evaluated 
      cross sections.                                             
                                                                  
  MT=  4 (n,n') cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
  MT= 16 (n,2n) cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
  MT= 22 (n,na) cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
  MT= 28 (n,np) cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
  MT= 51-91 (n,n') cross section                                  
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=102 Capture cross section                                    
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=103 (n,p) cross section                                      
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=104 (n,d) cross section                                      
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=105 (n,t) cross section                                      
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=106 (n,He3) cross section                                    
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=107 (n,a) cross section                                      
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=111 (n,2p) cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=112 (n,pa) cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
  MT=115 (n,pd) cross section                                     
    Calculated with KALMAN code /3/.                              
                                                                  
MF=34 Covariances for Angular Distributions                       
  MT=  2 Elastic scattering                                       
    Calculated with KALMAN code /3/. The covariances of P1        
      components were only evaluated.                             
                                                                  
                                                                  
                                                                  
***************************************************************** 
       Nuclear Model Calculation with CCONE code /1/              
***************************************************************** 
                                                                  
  Models and parameters used in the CCONE calculation             
  1) Optical model                                                
    * optical model potential                                     
      neutron  omp: Kunieda,S. et al./4/ (+)                      
      proton   omp: Koning,A.J. and Delaroche,J.P./5/ (+)         
      deuteron omp: Lohr,J.M. and Haeberli,W./6/                  
      triton   omp: Becchetti Jr.,F.D. and Greenlees,G.W./7/      
      He3      omp: Becchetti Jr.,F.D. and Greenlees,G.W./7/      
      alpha    omp: McFadden,L. and Satchler,G.R./8/ (+)          
      (+) omp parameters were modified.                           
                                                                  
    * DWBA calculation                                            
           levels: 1,2,18 (see Table 1)                           
                                                                  
  2) Two-component exciton model/9/                               
    * Global parametrization of Koning-Duijvestijn/10/            
      was used.                                                   
    * Gamma emission channel/11/ was added to simulate direct     
      and semi-direct capture reaction.                           
                                                                  
  3) Hauser-Feshbach statistical model                            
    * Width fluctuation correction/12/ was applied.               
    * Neutron, proton, deuteron, triton, He3, alpha and gamma     
      decay channel were taken into account.                      
    * Transmission coefficients of neutrons were taken from       
      optical model calculation.                                  
    * The level scheme of the target is shown in Table 1.         
    * Level density formula of constant temperature and Fermi-gas 
      model were used with shell energy correction/13/.           
      Parameters are shown in Table 2.                            
    * Gamma-ray strength function of generalized Lorentzian form  
      /14/,/15/ was used for E1 transition.                       
      For M1 and E2 transitions the standard Lorentzian form was  
      adopted. The prameters are shown in Table 3.                
                                                                  
                                                                  
------------------------------------------------------------------
                              Tables                              
------------------------------------------------------------------
                                                                  
Table 1. Level Scheme of Cr-52                                    
  ---------------------------------                               
  No.  Ex(MeV)  J  PI,   DWBA: beta                               
  ---------------------------------                               
   0  0.00000   0  +                                              
   1  1.43409   2  +           0.21                               
   2  2.36963   4  +           0.05                               
   3  2.64690   0  +                                              
   4  2.76777   4  +                                              
   5  2.96479   2  +                                              
   6  3.11386   6  +                                              
   7  3.16174   2  +                                              
   8  3.41532   4  +                                              
   9  3.47225   3  +                                              
  10  3.61593   5  +                                              
  11  3.73960   2  +                                              
  12  3.77172   2  +                                              
  13  3.94850   2  +                                              
  14  4.01551   5  +                                              
  15  4.03920   4  +                                              
  16  4.10000   3  -                                              
  17  4.47000   3  -                                              
  18  4.56300   3  -           0.09                               
  19  4.61100   0  +                                              
  20  4.62732   4  +                                              
  21  4.70200   2  +                                              
  22  4.73000   4  +                                              
  23  4.74230   2  +                                              
  24  4.75032   8  +                                              
  25  4.80010   0  +                                              
  26  4.80619   6  +                                              
  27  4.81570   0  +                                              
  28  4.84130   0  +                                              
  ---------------------------------                               
                                                                  
Table 2. Level density parameters                                 
  --------------------------------------------------------        
  Nuclide      a*    Pair  Eshell       T      E0  Ematch         
            1/MeV     MeV     MeV     MeV     MeV     MeV         
  --------------------------------------------------------        
   Cr- 53  7.8100  1.6483 -1.1345  1.2832 -0.7530  9.9152         
   Cr- 52  6.6800  3.3282 -1.3204  1.6541 -0.9930 16.2114         
   Cr- 51  7.8300  1.6803 -1.0884  1.4788 -2.9231 13.9698         
    V- 52  7.1000  0.0000 -0.6140  1.2996 -2.0622  7.3847         
    V- 51  6.9100  1.6803 -0.6457  1.5346 -2.3344 12.8214         
    V- 50  7.0000  0.0000 -0.6353  1.4319 -3.1193  9.4496         
   Ti- 51  7.6300  1.6803 -0.3127  1.1333  0.1795  7.4616         
   Ti- 50  7.2500  3.3941 -0.4613  1.2919  1.1007 10.9863         
   Ti- 49  7.8800  1.7143  0.2445  1.1040 -0.1128  7.6316         
   Ti- 48  7.0700  3.4641  0.6643  1.4400 -0.8454 13.4405         
  --------------------------------------------------------        
                                                                  
Table 3. Gamma-ray strength function for Cr- 53                   
  --------------------------------------------------------        
  * E1: ER = 17.80 (MeV) EG = 6.50 (MeV) SIG =  88.00 (mb)        
  * M1: ER = 10.92 (MeV) EG = 4.00 (MeV) SIG =   1.49 (mb)        
  * E2: ER = 16.77 (MeV) EG = 5.47 (MeV) SIG =   1.18 (mb)        
  --------------------------------------------------------        
                                                                  
References                                                        
 1) Iwamoto,O.: J. Nucl. Sci. Technol., 44, 687 (2007).           
 2) Mihailescu,L.C. et al.: Nucl. Phys. A786, 1 (2007).           
 3) Kawano,T., Shibata,K.: JAERI-Data/Code 97-037 (1997) in       
    Japanese.                                                     
 4) Kunieda,S. et al.: J. Nucl. Sci. Technol. 44, 838 (2007).     
 5) Koning,A.J. and Delaroche,J.P.: Nucl. Phys. A713, 231 (2003)  
    [Global potential].                                           
 6) Lohr,J.M. and Haeberli,W.: Nucl. Phys. A232, 381 (1974).      
 7) Becchetti Jr.,F.D. and Greenlees,G.W.: Ann. Rept.             
    J.H.Williams Lab., Univ. Minnesota (1969).                    
 8) McFadden,L. and Satchler,G.R.: Nucl. Phys. 84, 177 (1966).    
 9) Kalbach,C.: Phys. Rev. C33, 818 (1986).                       
10) Koning,A.J., Duijvestijn,M.C.: Nucl. Phys. A744, 15 (2004).   
11) Akkermans,J.M., Gruppelaar,H.: Phys. Lett. 157B, 95 (1985).   
12) Moldauer,P.A.: Nucl. Phys. A344, 185 (1980).                  
13) Mengoni,A. and Nakajima,Y.: J. Nucl. Sci. Technol., 31, 151   
    (1994).                                                       
14) Kopecky,J., Uhl,M.: Phys. Rev. C41, 1941 (1990).              
15) Kopecky,J., Uhl,M., Chrien,R.E.: Phys. Rev. C47, 312 (1990).