42-Mo- 94

 42-MO- 94 JNDC       EVAL-AUG89 JNDC FP NUCLEAR DATA W.G.        
                      DIST-MAR02 REV4-SEP01            20010904   
----JENDL-3.3         MATERIAL 4231                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
HISTORY                                                           
84-10 Evaluation for JENDL-2 was made by JNDC FPND W.G./1/        
89-08 Modification for JENDL-3 was made/2/.                       
90-10 mf=5: Spectra at threshold energies were modified.          
93-10 JENDL-3.2.                                                  
      Compiled by T.Nakagawa (ndc/jaeri)                          
                                                                  
     *****   modified parts for JENDL-3.2   ********************  
      (3,2), (3,4), (3,51-91), (3,16), (3,17), (3,22), (3,28)     
      (4,16-91)                                                   
      (5,16-91)                                                   
            These data were adopted from JENDL fusion file        
      (3,32)        deleted                                       
     ***********************************************************  
                                                                  
     -------------------------------------------------------------
      JENDL fusion file /3/  (as of Oct. 1993)                    
        Evaluated by K.Kosako(nedac) and S.Chiba (ndc/jaeri)      
        compiled by K.Kosako                                      
                                                                  
          The inelastic scattering, (n,2n), (n,3n), (n,np), (n,na)
        cross sections were calculated with sincros-ii system/4/. 
        The other cross sections were taken from JENDL-3.1.  mf=6 
        of mt=16, 17, 22, 28 and 91 were created with f15tob      
        program /3/ in which Kumabe's systematics/5/ was used.    
        The precompound/compound ratio was calculated by the      
        sincros-ii code system/4/.                                
          Optical-model, level density and other parameters used  
        in the sincros-ii calculation are described in ref./4/.   
        Level schemes were determined on the basis of ENSDF/6/.   
     -------------------------------------------------------------
     -------------------------------------------------------------
01-08 Compiled by K.Shibata (ndc/jaeri) for JENDL-3.3.            
      *****   modified parts for JENDL-3.3   *********************
      (1,451)         Updated.                                    
      (3.1)           Revised.                                    
      (3,2)           Re-calculated.                              
      (3,203-207)     Added.                                      
      (3,251)         Deleted.                                    
      (4,2)           Transformation matrix deleted.              
      (4,16-91)       Deleted.                                    
      (5,16-91)       Deleted.                                    
      (6,16-91)       Taken from JENDL fusion file.               
      (12,102)        Added.                                      
      (13,3)          Added.                                      
      (14,3),(14,102) Added.                                      
      (15,3),(15,102) Added.                                      
      ************************************************************
                                                                  
                                                                  
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 20 keV         
    Evaluation was made by Kikuchi et al./7/ on the basis of the  
    following experimental data:                                  
      capture : Weigmann et al./8/, Musgrove et al./9/            
    Average radiative widths were assumed to be 0.135 eV and 0.175
    eV for s-wave and p-wave resonances, respectively.            
  Unresolved resonance region : 20 keV - 100 keV                  
    The neutron strength functions, S0, S1 and S2 were 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 = 0.369e-4, S1 = 5.479e-4, S2 = 0.365 e-4, Gg = 0.230 eV   
    Do = 1101  eV, R  = 6.699 fm.                                 
                                                                  
  calculated 2200-m/s cross sections and res. integrals (barns)   
                     2200 m/s               res. integ.           
      total           6.011                    -                  
      elastic         5.998                    -                  
      capture         0.01311                  1.40               
                                                                  
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/10/, 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 et al./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-  
  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.  The energy dependence of spin cut-off parameter in
  the energy range below E-joint (Ex) is due to Gruppelaar/19/.   
                                                                  
     For JENDL-3.2, data of neutron emitting reactions were       
  adopted from JENDL fusion file.  The calculation was made with  
  sincros-ii system/4/ by adoptig Walter-Guss omp modified by     
  Yamamuro/4/ for neutrons, Lemos omp modified by Arthur and      
  Young/20/ for alpha, the same omp's as the pegasus calculation  
  for other charged particles and standard level density parame-  
  ters of sincros-ii system.                                      
                                                                  
  mt = 1  Total                                                   
    Below 500 keV, spherical optical model calculation was        
    adopted. Omp in Table 1 and casthy were used.  Above 500 keV, 
    spline-fitting to the elemental data measured by Foster and   
    Glasgow/25/, Lambropoulos et al./26/ and Poenitz and Whalen   
    /27/ was made.                                                
                                                                  
  mt = 2  Elastic scattering                                      
    Calculated as (total - sum of partial cross sections).        
                                                                  
  mt = 4, 51 - 91  Inelastic scattering                           
    Taken from JENDL fusion file.  The level scheme was taken from
    ref./6/  Cntributions of the direct process was calculated    
    for the levels marked with '*'.                               
                                                                  
                                                                  
           no.      energy(MeV)    spin-parity (direct process)   
           gr.       0.0             0  +                         
            1        0.8711          2  +          *              
            2        1.5737          4  +                         
            3        1.7425          0  +                         
            4        1.8643          2  +                         
            5        2.0674          2  +                         
            6        2.2952          4  +                         
            7        2.3932          2  +                         
            8        2.4235          6  +                         
            9        2.5339          3  -          *              
           10        2.5668          4  +                         
           11        2.6115          5  -                         
           12        2.7398          1  +                         
           13        2.7681          4  +                         
           14        2.8058          2  +                         
           15        2.8359          3  +                         
           16        2.8702          2  +                         
           17        2.8724          6  +                         
           18        2.9558          8  +                         
           19        2.9651          2  +                         
      Levels above 2.965 MeV were assumed to be overlapping.      
                                                                  
  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                                  
    Adopted from JENDL fusion file.                               
                                                                  
  mt = 102  Capture                                               
    Spherical optical and statistical model calculation with      
    casthy/10/ 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 (=1.966e-4) was adjusted to   
    reproduce the experimental capture cross section of 54.5      
    milli-barns at 100 keV measured by Musgrove et al./9/.        
                                                                  
  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                                
  mt =111  (n,2p) cross section                                   
    These reaction cross sections were calculated with the pre-   
    equilibrium and multi-step evaporation model code pegasus     
    /11/.                                                         
                                                                  
    The Kalbach's constant k (= 151.7 ) was estimated by the      
    formula derived from Kikuchi-Kawai's formalism/22/ and level  
    density parameters.                                           
                                                                  
    Finally, (n,p) and (n,alpha) cross sections were normalized to
    the following values at 14.5 MeV:                             
      (n,p)         55.10  mb (systematics of  Forrest/23/)       
      (n,alpha)     17.50  mb (recommended by  Forrest/23/)       
                                                                  
  mt=203  Total proton production                                 
    Sum of mt=28, 103 and 2*(111).                                
                                                                  
  mt=204  Total deuteron production                               
    Equal to mt=104.                                              
                                                                  
  mt=205  Total triton production                                 
    Equal to mt=105.                                              
                                                                  
  mt=206  Total He-3 production                                   
    Equal to mt=106.                                              
                                                                  
  mt=207  Total alpha production                                  
    Sum of mt=22 and 107.                                         
                                                                  
mf = 4  Angular distributions of secondary neutrons               
  mt = 2                                                          
    calculated with casthy/12/.                                   
  mt = 51-69                                                      
    Taken from JENDL fusion file data which was calculated with   
    casthy and dwuck/24/ in the sincros-ii system.                
                                                                  
mf = 6  Energy-angle distributions of secondary particles         
  mt = 16,17,22,28,91                                             
    Based on Kumabe's systematics/5/.                             
  mt = 203,204,205,206,207                                        
    Based on Kalbach's systematics/28/.                           
                                                                  
mf =12  Photon production multiplicities                          
  mt = 102 (below 420 keV)                                        
    Calcuated with casthy.                                        
                                                                  
mf =13  Photon production cross sections                          
  mt = 3 (above 420 keV)                                          
    Fitted with the empirical formula by Howerton and Plechaty    
    /29/ based on the experimental data/30/.                      
                                                                  
mf =14  Photon angular distributions                              
  mt = 3,102                                                      
    Assumed to be isotropic.                                      
                                                                  
mf =15  Continuous photon energy spectra                          
  mt = 3                                                          
    Fitted with the empirical formula by Howerton and Plechaty    
    /29/ based on the experimental data/30/, and compared with    
    experimental data measured by Yamamuro et al./31/.            
  mt = 102                                                        
    Calculated with casthy/10/.                                   
                                                                  
 *Note that gamma-ray produciton for mt=3 was made so as to       
  reproduce measured elemental data.                              
                                                                  
================================================================= 
<> 
================================================================= 
                                                                  
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         
                                                                  
Table 2  Level density parameters                                 
                                                                  
 nucl.    syst a(/MeV)   t(MeV)    c(/MeV)   Ex(MeV)   pairing    
 ---------------------------------------------------------------  
 40-Zr- 90     9.152e+00 8.222e-01 1.526e-01 5.383e+00 2.130e+00  
 40-Zr- 91     1.036e+01 8.000e-01 7.822e-01 5.057e+00 1.200e+00  
 40-Zr- 92     1.088e+01 8.192e-01 5.122e-01 6.429e+00 1.920e+00  
 40-Zr- 93     1.298e+01 7.000e-01 1.273e+00 5.183e+00 1.200e+00  
                                                                  
 41-Nb- 91  *  9.464e+00 7.143e-01 3.924e-01 3.082e+00 9.300e-01  
 41-Nb- 92     1.040e+01 8.410e-01 4.607e+00 4.477e+00 0.0        
 41-Nb- 93     1.250e+01 7.120e-01 2.205e+00 4.629e+00 7.200e-01  
 41-Nb- 94     1.281e+01 7.230e-01 7.763e+00 4.250e+00 0.0        
                                                                  
 42-Mo- 92     1.064e+01 7.770e-01 2.062e-01 5.938e+00 2.210e+00  
 42-Mo- 93     1.125e+01 7.800e-01 9.792e-01 5.457e+00 1.280e+00  
 42-Mo- 94     1.301e+01 6.850e-01 3.417e-01 5.770e+00 2.000e+00  
 42-Mo- 95     1.360e+01 7.150e-01 1.847e+00 5.835e+00 1.280e+00  
 ---------------------------------------------------------------  
  syst:  * = ldp's were determined from systematics.              
                                                                  
  Spin cut-off params were calculated as 0.146*sqrt(a)*a**(2/3).  
  in the casthy caluculation. Spin cut-off factors at 0 MeV were  
  assumed to be 7.761 for Mo-94 and 6.184 for Mo-95.              
                                                                  
References                                                        
 1) Aoki, T. et al.: Proc. Int. Conf. on Nuclear Data for Basic   
    and Applied Science, Santa Fe., Vol. 2, p.1627 (1985).        
 2) Kawai, M. et al.: J. Nucl. Sci. Technol., 29, 195 (1992).     
 3) Chiba, S. et al.: JAERI-M 92-027, p.35 (1992).                
 4) Yamamuro, N.: JAERI-M 90-006 (1990).                          
 5) Kumabe, I. et al.: Nucl. Sci. Eng., 104, 280 (1990).          
 6) ENSDF: Evaluated Nuclear Structure Data File, BNL/NNDC.       
 7) Kikuchi, Y. et al.: JAERI-M 86-030 (1986).                    
 8) Weigmann, H. et al.: 1971 Knoxville, 749 (1971).              
 9) Musgrove A.R.de L.: Nucl. Phys., A270, 108 (1976).            
10) Igarasi, S. and Fukahori, T.: JAERI 1321 (1991).              
11) Iijima, S. et al.: JAERI-M 87-025, p. 337 (1987).             
12) Iijima, S. and Kawai, M.: J. Nucl. Sci. Technol., 20, 77      
    (1983).                                                       
13) Perey, F.G: Phys. Rev. 131, 745 (1963).                       
14) Huizenga, J.R. and Igo, G.: Nucl. Phys. 29, 462 (1962).       
15) Lohr, J.M. and Haeberli, W.: Nucl. Phys. A232, 381 (1974).    
16) 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).                                                       
17) Gilbert, A. and Cameron, A.G.W.: Can. J. Phys., 43, 1446      
    (1965).                                                       
18) Iijima, S., et al.: J. Nucl. Sci. Technol. 21, 10 (1984).     
19) Gruppelaar, H.: ECN-13 (1977).                                
20) Arthur, E.D. and Young, P.G.: LA-8626-MS (1980).              
21) Benzi, V. and Reffo, G.: CCDN-NW/10 (1969).                   
22) Kikuchi, K. and Kawai, M.: "Nuclear Matter and Nuclear        
    Reactions", North Holland (1968).                             
23) Forrest, R.A.: AERE-R 12419 (1986).                           
24) Kunz, P.D.: private communication.                            
25) Foster, Jr.D.G. and Glasgow, D.W.: Phys. Rev., C3, 576 (1971).
26) Lambropoulos, P. et al.: Nucl. Phys., A201, 1 (1973).         
27) Poenitz, W.P. and Whalen, J.F.; ANL/NDM-80 (1983).            
28) Kalbach, C. : Phys. Rev. C37, 2350(1988).                     
29) Howerton, S.T. and Plechaty, E.F.: Nucl. Sci. Eng., 32, 178   
    (1968).                                                       
30) Morgan, G. and Newman, N.: ORNL-TM-5097 (1975).               
31) Yamamuro, N. et al.: 1982 Antwerp, 152 (1982).