Be metal

 be metal  LANL       EVAL-apr93 MACFARLANE                       
 ref. 3 (1994)        DIST-MAY10                       20100309   
----JENDL-4.0         MATERIAL   26                               
-----THERMAL NEUTRON SCATTERING DATA                              
------ENDF-6 FORMAT                                               
==================================================================
 The data were taken from ENDF/B-VI.8.                            
==================================================================
                                                                  
  temperatures = 296, 400, 500, 600, 700, 800, 1000, 1200         
                                                                  
 history                                                          
 -------                                                          
 this evaluation was generated at the los alamos national         
 laboratory (apr 1993) using the leapr code.  the physical        
 model is very similar to the one used at general atomic          
 in 1969 to produce the original endf/b-iii evaluations           
 (see ref. 1).  tighter grids and extended ranges for alpha       
 and beta were used.  a slightly more detailed calculation        
 of the coherent inelastic scattering was generated.  of          
 course, the various constants were updated to agree with         
 the endf/b-vi evaluation of be.                                  
                                                                  
 theory                                                           
 ------                                                           
 the phonon dispersion curves were fitted by Schmunk et al        
 using a model of central forces that extend to the fifth         
 nearest neightbors (ref 2).  the phonon spectrum corresponding   
 to this model was calculated by the root sampling method,        
 and then used to compute s(alpha,beta). the coherent elastic     
 scattering cross section was computed using the known lattice    
 3tructure (hexagonal close-packed) and the debye-waller          
 integrals from the lattice dynamics model.                       
                                                                  
 references                                                       
 ----------                                                       
 1. j.u.koppel and d.h.houston, reference manual for endf thermal 
    neutron scattering data, general atomic report ga-8774        
    revised and reissued as endf-269 by the national nuclear      
    data center, july 1978.                                       
 2. r.e.schmunk, r.m.brugger, p.d.randolph, and k.a.strong,       
    phys. rev. 128,562 (1962).                                    
 3. r.e.macfarlane, new thermal neutron scattering files for      
    endf/b-vi release 2, los alamos national laboratory report    
    LA-12639-MS (ENDF-356) March 1994.