Re: Dust Loading on Air Samples for Alpha Activity

["Bates Estabrooks -WIPP Site - N.M." <besta@tis.eh.doe.gov>]

At 11:58 AM 9/25/96 -0500, you wrote:
>It is well known that nonradioactive dust on air samples, if not
>corrected for, can cause underestimation of air concentrations of alpha
>emitters.  Does anyone know of published data that gives curves or
>equations for calculating correction factors for dust loading on alpha
>air samples?  Of course one must know by some measurement the areal
>density of the dust loading in terms of mg-cm-2 for a filter.  And, one
>would know the alpha energy.  I would like a curve that, for a given
>alpha energy and counting geometry, would tell me, for example, that a
>dust loading of 1mg-cm2 would require multiplying the measured activity
>by 2 to get the actual alpha activity on the filter paper.  Then there
>is the complication of deposition of alpha activity as a function of
>depth in the dust layer.  One could always make the conservative
>assumption that all the alpha activity were under the entire thickness
>of dust.  But, maybe, if the contaminated aerosol were assumed to be in
>time uniformly deposited, the correction factor could take that into
>account.  Thanks in advance.  Al Tschaeche xat@inel.gov
>
>

Al;

We at the WIPP have contended with this issue extensively, since our Pu CAMs
have to operate in an environment of salt dust.

The people at ITRI in Albuquerque are the experts on this.  Since this is a
pretty convoluted topic, give me a call and we can talk.

Regards.

Bates Estabrooks
505-234-8470
Bates Estabrooks
Westinghouse Electric Corp.
WIPP-  Radiological  Ccontrols
505-234-8470
fax: 505-885-4562
besta@tis.eh.doe.gov

Comments expressed are my own; not my employer or U.S. DOE (unless otherwise
stated).