Re: Conversion of Half-life Years to Seconds

[Ted de Castro <tdc@XRAYTED.COM>]

Have you looked at 1/2 live references?  Seen all the different

numbers?  Many are not know to a sufficient precision to warrant the

concern - just pick one and use it!  (except the 365 - I use 365.25 and

leave it at that.)



"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

> 

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