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Re: Conversion of Half-life Years to Seconds
You're asking the wrong question. (While you're at it, do you also want to
account for leap years?) The real question is how to find accurate and
precise half life data. If you look at the literature, you'll often find wide
variations in half life data among the "standard" references. I took a quick
look, and found the following half life values for Pu-239: ICRP 38 shows a
half life of 24065 years, while Kocher shows a half life of 24131 years.
Which one is the "real" value? Who knows. In any event, the question of
whether a year has 365.24219 days or 365.25636 days is irrelevant.
BTW: Although I'm not an experimental physicist, I'd guess that, for
long-lived radionuclides, specific activity is the actual measured quantity,
which is then used to calculate half life. Rather than trying to calculate
specific activity with false precision from half life data, you should be
searching to literature for specific activity data.
The opinions expressed are strictly mine.
It's not about dose, it's about trust.
Curies forever.
Bill Lipton
liptonw@dteenergy.com
"Leo M. Lowe" wrote:
> I want to calculate relatively precisely the specific activities of
> radionuclides with half-lives that are given in units of years. This
> requires a conversion from "years" to seconds.
>
> So which "year" should I use: the calendar year (365 days), the mean solar
> year (365.24219 days), the sidereal year (365.25636 days), ....? (where 1
> day = 24 hours = 86,400 seconds).
>
> Which "year" is used by the standards organizations, such as NIST, when
> publishing half-lives?
>
> Regards,
>
> Leo M. Lowe, Ph.D., P.Phys.
> Principal, Senior Health and
> Environmental Physicist
>
> SENES Consultants Limited
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> llowe@senes.ca
> www.senes.ca
>
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