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    PR # 31239                                                                   
     We propose a new method to derive the Hubble constant by marking use        
     of intensity decrement of Fe-k lines at the central core region cause       
     d by a resonant scattering effect in an intercluster medium. Two clus       
     ters A644(z=0.0704) and A3266(z=0.0594) are selected for this purpose       
      under the conditions of high intensity,temperature,abundance and lum       
     inosity, and large angular size fit well to GIS field of view. The fi       
     nite optical depth of Fe lines is essential to derive the total amoun       
     t of gas and result in obtaining the absolute cluster size. The data        
     analysis of PV phase clusters indicates the usefulness of this method       
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