Re: Nd-144 -Reply

[David W Lee <lee_david_w@lanl.gov>]

Charlie: 

        Thank-you for this Nd-144 half-life information and history.  I was unaware that the half-life had been determined in 1954.  When doing my sealed source work, I try to use the latest version of the Table of Isotopes.  The latest version that I have is the 8th Ed., published in 1996, Firestone, Shirley, Baglin, Chu, and Zipkin, Editors.  This edition lists the half-life of Nd-144 as 2.29 E+15 yrs.  Your point is well taken; perhaps I am being a bit intellectually naive to presume that merely because I'm using the so-called latest edition of the Table of Isotopes, that such a "latest" listing contains the most accurate/currently accepted half-life value.  Best regards  David

At 04:06 PM 12/2/1998 -0600, you wrote:
>David,
>
>The half  life of Nd-144 was determined in 1954 but there seems to have been
>some disagreement about the value (2 E 15 vs 5 E 15 years). Essentially the
>present value was included in the 1967 edition of  "Table of Isotopes," by Lederer,
>Hollander and Perlman.  Also it was in the 1968 edition of the KAPL/GE "Chart of
>the Nuclides," by Holden and Walker.
>
>Charlie Willis
>caw@nrc.gov
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DAVID W. LEE
Los Alamos National Laboratory
Radiation Protection Services, ESH-12
PO Box 1663, MS K483
Los Alamos, NM  87545
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lee_david_w@lanl.gov