Re: Conversion of Half-life Years to Seconds

[Dimiter Popoff <tgi@cit.bg>]

I am not sure if this correction is necessary because of my non-native

English, but to me



" now that you know you have asked the wrong question, ..."



in the context of the message exchange on this thread means the same like



" now that you've been told you have asked the wrong question, ..." .





Again, I am also curious what the answer to the question is - and I

certainly believe it is a justified question to ask.

I would guess the answer is 365.25 for practical reasons (see my

former message, quoted below).



Dimiter





> Cc: <radsafe@list.Vanderbilt.Edu>

> To: Leo M. Lowe <llowe@senes.ca>

> From: Dimiter Popoff <tgi@cit.bg>

> Subject: Re: Conversion of Half-life Years to Seconds

> Date: Thu, 11 Dec 2003 0:05:30 +0200

> 

> Leo Lowe,

> 

> now that you know you have asked the wrong question, may I re-ask it:

> 

> > Which "year" is used by the standards organizations, such as NIST, when

> > publishing half-lives?

> 

> Several years back, when I was writing my spectrum evaluation software,

> I programmed the interactive nuclide library to switch the unit of the

> half-life every time you click it. 

>  I had the same question then - but given the issue was of no analytical

> concern, I just took 365.25 days/year and called it a day. Also, this was

> the better choice for me because in the sample report you can click and

> edit the date of any isotope and see what its activity was/will be then;

> this implies 365.25 precisely.

> 

>  I certainly would be curious if there is a "standard" for that.

> 

> Dimiter

> 

> --------------------------------------------------------------------

> Dimiter Popoff

> Transgalactic Instruments, Gourko Str. 25 b, 1000 Sofia, Bulgaria

> http://transgalactic.freeyellow.com

> 

> 

> 

> 

> > 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

> > 121 Granton Drive, Unit 12

> > Richmond Hill, Ontario

> > Canada L4B 3N4

> > Tel:    (905) 764-9380

> > Fax:    (905) 764-9386

> > llowe@senes.ca

> > www.senes.ca

> >

> 

************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/