ENTRY            M0692   20060731
SUBENT        M0692001   20060731                                 
BIB                 15         94                                 
TITLE      Photofission cross sections for 237Np in  the  energy  
            interval from 5.27 to 10.83 MeV.                      
AUTHOR     (L.P.GERALDO,R.SEMMLER,O.I.GONCALEZ,J.MESA,            
            J.D.T.ARRUDA-NETO,F.GARCIA,O.RODRIGUES)               
REFERENCE  (J,NSE,136,357,2000)                                   
INSTITUTE  (3BZLBZL,3BZLIPE,3BZLCTA,3BZLUSP)                      
FACILITY   (REAC,3BZLIPE) IPEN  IAE-R1  MW  pool-type   research  
            reactor.                                              
INC-SOURCE (MPH) High-resolution  (4 - 20 eV)  gamma-rays,  with  
            discrete energies up to 10.83 MeV,  were produced by  
            thermal neutron  capture  in  30  different   target  
            materials, when   they   were  positioned  near  the  
            reactor core:                                         
                  Capture target    Gamma-ray energy, keV         
            ----------------------------------------------------  
                         Yb                  5265.70              
                         S                   5420.50              
                         Dy                  5607.75              
                         Hf                  5723.50              
                         In                  5891.90              
                         Hg                  5966.20              
                         Y                   6080.49              
                         Er                  6228.23              
                         Na                  6395.40              
                         Ca                  6419.90              
                         Nd                  6501.70              
                         V                   6517.26              
                         Gd                  6748.70              
                         Ti                  6760.13              
                         Be                  6809.41              
                         As                  7019.45              
                         Sm                  7214.20              
                         Mn                  7243.79              
                         Pb                  7367.70              
                         Cl                  7413.80              
                         Se                  7418.47              
                         Fe                  7631.13              
                         Al                  7723.85              
                         K                   7770.22              
                         Zn                  7863.30              
                         Cu                  7914.50              
                         Cd                  8484.80              
                         Ni                  8998.80              
                         Cr                  9720.30              
                         N                  10829.18              
SAMPLE     The sample consisted of  36.10  (0.13  mg)  of  237Np  
            deposited in  form  of  NpO-2 on six titanium disks,  
            forming an active diameter of ~ 40 mm.                
DETECTOR   (TRD) Makrofol KG foils (10 micron thickness) in form  
            of a sandwich (2PI geometry).                         
METHOD     (EXTB,STTA)                                            
ANALYSIS   (UNFLD) The method of unfolding of cross section data  
            for definite gamma-lines  from  those  obtained  for  
            composition of  all   gamma-lines    used   employed  
            least-squares  methods  and  the  covariance  matrix  
            methodology.                                          
REL-REF    (N,,O.L.GONCALES+,J,NSE,132,135,1999) The  method for  
            unfolding.                                            
ERR-ANALYS (DATA-ERR) The  overall  uncertainties were estimated  
            by summing in quadrature all following components:    
                    Error Sources                Range (%)        
             ---------------------------------------------------  
             Random errors                                        
             (0 % uncorrelated errors)                            
             Fission track counting             0.43 - 6.83       
             Gamma-ray counting                 0.19 - 4.83       
             ---------------------------------------------------  
             Systematic errors                                    
             (100 % completely correlated errors)                 
             237Np deposit mass                     0.35          
             Gamma-ray intensity ratio              0.29          
             Gamma-ray intensity attenuation        0.34          
             Fission track calibration factor       0.80          
             Ge(Li) calibration factor          0.77 - 3.51       
COMMENT    Photofission cross  sections  for  237  Np  have been  
            measured as a function of energy,  in  the  interval  
            from 5.27  to 10.83 MeV.  The gamma-ray spectra were  
            those produced by thermal  neutron  capture,  in  30  
            different target  materials,  as  a  tangential beam  
            hole of the Instituto  de  Pesquisas  Energeticas  e  
            Nucleares IAE-R1  1-MW research reactor.  The set of  
            experimental data  has   been   unfolded   employing  
            least-squares methods   and  the  covariance  matrix  
            methodology. The   determined   photofission   cross  
            sections for  237Np,  together  with  the   complete  
            orrelation  matrix  for  the  involved  errors,  are  
            presented   and   are   compared    with    previous  
            measurements   reported   in   the   literature.   A  
            statisticl calculation for the 237  Np  photofission  
            cross  sections  was performed,  and the results are  
            compared with the experimental data.                  
STATUS     (TABLE) Data from the Table III were  compiled at the  
            Russia MSU SINP CDFE by V.Varlamov.                   
HISTORY    (20060626C)                                            
ENDBIB              94                                            
NOCOMMON             1          3                                 
ENDSUBENT           97