Re: FOCUSED ION BEAM SYSTEMS

[LIPTONW@detroitedison.com]

My experience with similar devices is limited and occurred almost 20 years, 
ago, but I did have a concern worth noting.  The device I encountered is 
probably different, in that it used an electron beam to "sputter" the material 
onto a thin target.  In this case, the operator had to view the process 
through a leaded glass eyepiece.  He accidently broke the eyepiece.  Then, 
concerned that someone would be angry, he replaced the broken leaded glass 
with plexiglass without telling anyone.  We did find detectable x-rays at the 
eyepiece.  A rule of thumb is that any electrical device which accelerates 
electrons through more than 10,000 volts has the potential to produce x-rays.  
This includes hi voltage switching equipment.   
 
Bill Lipton 
The opinions expressed are strictly mine.

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• To: Multiple,recipients,of,list,radsafe@romulus.ehs.uiuc.edu
• Subject: FOCUSED ION BEAM SYSTEMS
• From: "radsafe@romulus.ehs.uiuc.edu" <radsafe@romulus.ehs.uiuc.edu>
• Date: 02 Jul 96 11:04:25
• Reply-to: radsafe@romulus.ehs.uiuc.edu

From: SHAND



         Anyone have experience surveying ion implantation devices
         for 150 kV focused ion beam systems.  My only experience
         with this type of device produced no exposures above
         background when using a Ludlum ion chamber on the outer
         cylinder housing during operations.  Dopants of silicon
         will be used for transistor fabrications, and possibly
         Arsenic ions (doubly charged) for energies up to 300 keV.


         Thanks.


         steve
         umcp

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