Email from Jim:

Date: Thu, 23 Sep 2004 17:43:58 -0500
From: Jim Birchall 
To: Juliette Mammei , Roger Carlini ,
     Klaus Grimm , Mark Pitt ,
     Neven Simicevic , Greg Smith ,
     Allena Opper , Richard Jones ,
     Norman Morgan , Mike Finn ,
     David Armstrong , Yongguang Liang ,
     Shelley Page , Dave Mack ,
     Tony Forest 
Subject: Collimator material

Here's the link to info on the Cu-Pb alloy Paul Brindza found for the 
collimator material. It's 70% Cu by weight, 25% Pb, 5% Sn, density 9300 
kg/m3.

Jim


http://www.anchorbronze.com/c94300.htm