RE: Radium Half Life (was Alarms at Borders)

["Neil, David M" <neildm@id.doe.gov>]

"Radium D" (Pb210) and "Radium E" (Bi210) are old names for radium daughters. Pb210 has a 22.3 year half-life, and Bi210 a 5+ day half-life.  So everybody was right, as far as it went.



Dave Neil



-----Original Message-----

From: Richard L. Hess [mailto:lists@richardhess.com]

Sent: Wednesday, January 12, 2005 5:30 PM

To: radsafe@list.vanderbilt.edu

Subject: Radium Half Life (was Alarms at Borders)





At 05:52 PM 1/12/2005 -0500, I wrote:



>The radium check sources have substantially reduced output due to the 

>relatively short half-life, while the uranium check sources are 

>essentially at their initial radioactivity.



Thanks to everyone reminding me that radium's half life is  1600-1620 years.



The manual (which I used as my source of information) for the Lionel CD 

V-700 Model 6B from 1962 states "The Radium D + E beta source 

...half-life...is approximately 22 years."



So, whatever I have it tracked that estimate (within the appropriate 

resolution).



It was the 22 years which I was referring to as stated in the manual and 

confirmed (by cross-checking two CD V-700s against their respective check 

sources.



Cheers,



Richard 





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