RE: Looking for vendor-polyethylene pig for neutron source

[Doug Aitken <daitken@sugar-land.oilfield.slb.com>]

At 09:21 AM 11/11/2003 +0200, you wrote:

>Bobby,

>Traditionally a sturdy drum filled with wax (optional borax added) was 

>often used with a source-sized hole down the middle to store a neutron 

>source. If that is considered a fire hazard, water (again with borax 

>optional) could be considered.  If most of the (thermalized)neutrons are 

>captured in boron, the gamma energy is about 480 keV, compared with the 

>rather penetrating 2.22 MeV if captured in hydrogen.

>Chris Hofmeyr



Building on this, a highly effective shielding (and very cheap compared 

with boron-loaded poly) can be made by filling your shield with borax 

granules and hydrating them to allow formation of a crystal lattice.

Borax technical grade granules can be obtained from many vendors - e.g. Van 

Waters & Rogers here in Houston. Make sure to get true Borax, B037441 is 

this company's order number, (sodium tetraborate decahydrate, also referred 

to as 10 mol by this vendor).

Fill your shield half full with tap water. Pour Borax granules into the 

shield, dispersing when it piles up above the water level. Maintain the 

water level above the Borax granules at all times. As the shield fills, 

Borax will displace the water which will run out of the shield as the 

granules take their place. Stir the mixture to ensure that air does not 

become trapped. Continue filling the shield until all water is displaced 

with borax and the shield is completely filled. The Borax granules will 

pack into a solid cake and will remain moist. Allow the shield to sit for a 

minimum of 48 hours to allow the water and borax to settle and also allow 

the borax to crystallize.



Regards





Doug Aitken		Schlumberger Drilling and Measurements QHSE 

Advisor

Phone (Sugarland):   	281 285-8009

Phone (Home office): 	713 797-0919	

Phone (Cell): 		713 562-8585

Principal E-mail: jdaitken@earthlink.net

Schlumberger E-mail: daitken@sugar-land.oilfield.slb.com

Mail: 	300 Schlumberger Drive MD2, Room 111

	Sugar Land, TX 77478









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