Thorium Oxide - Where could I buy small quantity?

Hello
I am developing medium pressure mercury lamps and in order to protect the electrodes and increase its life it is necessary to coat them with
thorium oxide.
In Brazil it is not easy to find this material. Could some one tell me where could I buy small quantities, in powder, of thorium oxide?
Best Regards,
Marcio Moraes - snipped-for-privacy@visioncure.com.br
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
in article snipped-for-privacy@uni-berlin.de, Dirk Bruere at Neopax at snipped-for-privacy@neopax.com wrote on 11/16/04 3:30 AM:

In the US at least, most use yttrium oxide now.
Bill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 16 Nov 2004 11:30:50 +0000, Dirk Bruere at Neopax

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&categoryX289&item852756074&rd=1&ssPageName=WDVW
w.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.