******************************************************                         
    PR # 31108                                                                   
     Tycho has been observed with ASCA in PV phase, however the observatio       
     n mode of SIS was bright mode. We request an observation of Tycho wit       
     h faint mode. In this mode, we can obtain best energy  resolution of        
     SIS. Spatially resolved high resolution spectroscopy  enables us to m       
     easure the ionizing stat of heavy elements and plasma parameters. The       
     se parameters are crucial to study the dynamical and chemical structu       
     re of Tycho, which also provide strong constraints on theoretical mod       
     els of Type 1 supernova explosion and mixing of ejecta.                     
                                                                                 
                                                                                 
                                                                                 
                                                                                 
  ******************************************************