RE: Shielding Material

[John Jacobus <crispy_bird@YAHOO.COM>]

Basically, cerrobend was employed to replaced lead in

making "shadow shields" in radiation teletherapy.   It

is easy pour into styrofoam molds, and mount to

plexiglass holders using sheet metal screws.  I have

worked with it as blocks, but not as sheets, so I do

not know how ductile it is.  



However, cerrobend (Melting point is 158° F.) is 50

percent bismuth, 26.7 percent lead, 13.3 percent tin,

10 percent cadmium.  Cadmium is a known carcinogensis.

 We were using another product (cerrolow?) that did

not contain the cadmium



Obviously, the Web site should be

http://www.mcmaster.com





--- KSmith <teraboat@PRODIGY.NET> wrote:

> Bob,

>  

> They use a lot of this line of alloy to make blocker

> trays for linear accelerators and radiation therapy

> simulators. They usually cast the blocks in

> Styrofoam molds and heat it in a big coffee urn.

> (most often used "cerrobend" or "cerrolow" ` 185

> degree F. melt point for safety reasons.) Machines

> well if you don't let it get too hot. Not as nearly

> as "squishey" as plain lead.

> Just a thought. ~4" stops 1meV. Don't know about

> plating though.

> Available at McMaster-Carr (http://mcmaster.com)

> retailer.

>  

> Good Luck

>  

> Karl Smith

> KSmith@KnoRad.com

> 804-749-4381

>  

>  

>  

> Cerrobase: Melting point is 255° F. Composition is

> 55.5 percent Bismuth, 44.5 percent Lead.

> 

> 

> 

> 







=====

+++++++++++++++++++

"We cannot escape danger, or the fear of danger, by crawling into bed and pulling the covers over our heads."

-- Franklin Delano Roosevelt



-- John

John Jacobus, MS

Certified Health Physicist

e-mail:  crispy_bird@yahoo.com





	

		

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