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Re: External Dose Constants for Beta Emitters
There are rather important and obvious physics reasons for not having
specific dose constants for beta radiation, including the energy
distribution of the spectrum and the relatively large air attenuation and
change in energy spectrum. You can calculate the absorbed dose rate for
betas in air if you know the stopping power, which ranges over an order
of magnitude for the beta energy range 10 keV to 2 Mev. Cf. Brodsky,
Handbook of Radiation Protection and Measurement, pp. 627-628; Kathren,
Radiation Protection, p. 49. There are many other useful texts,
including the book by Turner, and the advanced works (Hine and Brownell,
an oldie but goodie, Attix, Roesch and Tochilin, Kase etc.) to name a few.
Ron Kathren
On Thu, 25 May 1995
VFINELLI@ACC.FAU.EDU wrote:
> Radsafenetters, I am not a HP although I subscribe to this
> list. Many years ago I have studied Radiochemistry,
> attended radiation safety courses and used radioisotopes
> (low levels) in my research activities, but I do not recall
> to have ever known the existance of tables reporting
> Specific Dose Constants for beta emitters. There are
> tables for Specific Gamma Ray Dose Constants in units of
> (mSv/h)MBq at 1 meter from a point source, but I have not
> found similar tables for beta emitters, not even for hard
> beta radiation. Could any radsafenetter out there help me
> to estimate the external dose-equivalent rate from an
> unshielded point sources at a distance of 1 meter or 1 foot
> (or whatever unit) for the following nuclides: H-3, C-14,
> P-32, P-33, S-35? Thanks for your help.
> P.S. Someone told me that the dose-equivalent rate for H-3
> at 1 foot from the point source is 1 (mrem/h)mCi. Is this
> an acceptable value?
> Vincent N. Finelli, Dir.
> Environmental Heath & Safety
> Florida Atlantic University
> Boca Raton, FL 33431
> E-mail: VFinelli@acc.fau.edu
>
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