Re: Scanning Electron Microscopes

["Clarence Dittman" <Clarence.Dittman@tdh.state.tx.us>]

Date sent:      	Wed, 8 Jul 1998 11:49:00 -0500 (CDT)
Send reply to:  	radsafe@romulus.ehs.uiuc.edu
From:           	Erin Lambert <eclare@purdue.edu>
To:             	Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Subject:        	Scanning Electron Microscopes

> Just a quick request to everyone,
> 
> I am researching radiation safety concerns for Scanning Electron Microscopes.
> I am not finding much information on my own so  I would like to know if any of
> you have set up a SEM program at any of your facilities.  I found some information
> at the Lawrence Livermore site but not much else.
> 
> If anyone knows of any regulations on SEMs or anywhere that I can find any 
> information on this topic, I would GREATLY appreciate it!
> 
> Thank you in advance,
> 
> Erin Lambert
> Health Physicist
> Department of Radiological & 
>   Environmental Management
> Purdue University
> eclare@purdue.edu
> 765-494-2721

SEM's do not constitute a radiation hazard.  The bremstralung for the impact of 
the electron beam on the targer is so low an energy that it can not penetrate 
the glass envelope.  If the glass envelope is cracked or broken, you can not 
maintain the vacuum necessary to generate the electron beam.  These devices 
are required to be registered by most state radiation control agencies because 
they are designed to produce a beam of radiation (electrons in his case.).  In 
answer to your real question, I suggest contacting you local state radiation 
control agency for any applicable regulations.  Texas Department of Health 
Bureau of Radiation Control has a web page from which the "Texas Regulations 
for Control of Radiation" can be downloaded.  The only applicable regulations 
would be registration requirements.  No radiation safety problem exists.

  Again, this is my own opinion
Clarence W. Dittman, Health Physicist
Radiation Control Program Manager
Texas Department of Health
Public Health Region 7
2408 South 37th Street
Temple, Texas 76504-7168
(254) 778-6744
Fax (254) 778-4066
Clarence.Dittman@tdh.state.tx.us