From: henry@spsystems.net   
      
   In article ,   
   Tommy   wrote:   
   >> How do you make a still that can process fluids in Zero-G?   
   >   
   >could you ionize the gas then accelerate it through a magnetic field to   
   >seperate it by molecular weight?   
      
   Unfortunately, the mass flow through such a system is tiny.  Space-charge   
   problems limit the beam current -- when the ion density in the beam gets   
   high enough, not only does it start to spread of its own accord, but it   
   distorts the fields used to accelerate the ions -- even with the use of   
   some clever tricks.  And it's difficult to ionize a large fraction of the   
   material, so non-ionized gas gets everywhere and messes things up if you   
   try for too strong a flow.   
      
   The "calutron" isotope separator built for the Manhattan Project, the size   
   of a small car, processed a few grams of material per day.  Energy use was   
   huge and maintenance loads were high.  That was a harder problem, mind   
   you, but you'd hit the same fundamental limits.  Doing any sort of useful   
   materials processing that way is basically impractical.   
      
   (The Manhattan Project filled a huge building with over a thousand   
   calutrons, and used them to do the uranium enrichment for the Hiroshima   
   bomb.  Once the first gaseous-diffusion enrichment plant came on line,   
   most of the calutrons were immediately shut down and scrapped.)   
   --   
   "Think outside the box -- the box isn't our friend."    |   Henry Spencer   
                                   -- George Herbert       | henry@spsystems.net   
      
   --- SoupGate-Win32 v1.05   
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