Re: Depleted U sources

[Chris Alston <alstonc@odrge.odr.georgetown.edu>]

You don't make it explicit what kind of sources you want, but it's implied
that you mean a certified standard source of beta radiation. The dose rate
at contact (tissue depth of 7mg cm^-2) with a DU slab of infinite density
(=/> 1/8 inch, I think) is 230 mrad h^-1. Certfied standards are usually
quoted with error bars @ +/- 20%. Eberline Instruments sells them:
(800)678-7088; and so does Isotope Products Laboratories: (818)843-7000. IPL
may also sell standards suitable for the calibration of instruments for
contamination surveys; I know that Amersham does. Note that, if you don't
need a certified standard, and you have colleagues who work with medical
linacs, some of the older models, e.g., Varian Clinac 4/100 and 6/100, used
DU (alloyed with Ti, which was only 0.75%) for the collimating jaws and gun
shield disks. Hint: the collimators are easily accessible, and VERY large.
P.S. Eberline's plaques are sheathed in a rather brittle plastic wrap (or
they were ten years ago); IPL's are gold-plated, and cost 150% more, last I
knew.

Good luck
chris alston
alstonc@odrge.odr.georgetown.edu


 At 02:09  04/23/98 -0500, you wrote:
>Can anyone out there recommend a supplier for depleted uranium sources?  
>Also, how does one establish a pedigree on these types of sources.
>
>It seems everyone has a different number for dose rate on contact, but 
>my experience with two such places indicates there probably isn't really 
>a difference, or that it is insignificant as measured by a dosimeter.
>
>Thanks,
>
>Rob
>
>
>Robert J. Gunter, M.Sc. 
>Health Physicist
>ICN Dosimetry Service
>ICN Plaza
>3300 Hyland Avenue
>Costa Mesa, CA  92626
>Ph:  800 548-5100 X 2414
>     +714 545-0100 X 2414
>Fax: +714 668-3149
>Email: rjgunter@icnpharm.com
>
>
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