XPost: sci.physics   
   From: hwabnig@.-   
      
   Doing some repair work on scintillator probes for gamma and beta   
   radiation I have to replace the  metalized Mylar cover.   
   Trying with 11 µm kitchen aluminium failed firsthand.   
      
   The Mylar foil is only 4 µm total but worked fine before in subdued   
   daylight. I do not know what metal is used on the Mylar.   
      
   Why the kitchen aluminium fails is unclear to me,   
   Possibly it has small invisible pores which let pass some light.   
      
   The question is, how thick must an aluminum layer be   
   to block light 100%. Cannot find reasonable data.   
   Google becoming more and more useless,   
   returning about 100000 school projects with no information.   
      
   w.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)