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RE: Gamma Energies online: a cautionary tale
- To: 'Arvic, Harms';, 'Mitchell, Davis';, 'Radsafepost'
- Subject: RE: Gamma Energies online: a cautionary tale
- From: NIXON, Kanata <Grant>
- Date: Mon, 7 Jul 2003 15:59:48 -0600
Dear Arvic,
I missed your point regarding this merely being a Q-value for EC. My problem
is with the table heading. It would have me believe that this is a handy
list of betas/electrons from 103Pd along with their relative intensity. One
has to look at the "decay mode" specifier must be consulted in order to
interpret the data as being EC and not beta emission. This "decay mode"
column looks much like a "decay type" one.
Thank you for your clarification.
Grant
-----Original Message-----
From: NIXON, Grant (Kanata)
Sent: Monday, July 07, 2003 11:23 AM
To: 'Arvic Harms'; NIXON, Grant (Kanata); 'Mitchell Davis'; Radsafepost
Subject: RE: Gamma Energies online: a cautionary tale
Hi Arvic,
Thank you for your comments.
Here is the table, as taken from the web site:
Betas from 103Pd (16.991 d 19)
----------------------------------------------------------------------------
----
Eb endpoint (keV) Ib (%) Decay mode
----------------------------------------------------------------------------
----
6,26 0.0040 2 e
185,69 0.0248 8 e
248,12 0.00044 11 e
503,34 99.9 1 e
543,1 0.10 e
----------------------------------------------------------------------------
----
It seems to me that the information provided indicates the end-point beta
energy as 503.34 keV and the frequency as 99.9(1)%. I do understand that
this characterizes a beta-decay spectrum.
The point is this: there IS NO SUCH BETA DECAY for this isotope!
Best regards,
Grant
-----Original Message-----
From: Arvic Harms [mailto:Arvic.Harms@npl.co.uk]
Sent: Monday, July 07, 2003 11:07 AM
To: 'NIXON, Grant (Kanata)'; Arvic Harms; 'Mitchell Davis'; Radsafepost
Subject: RE: Gamma Energies online: a cautionary tale
Dear Grant,
Although I agree you should use caution when using tabulated data, I do
not agree with your conclusions regarding the "electron emissions at
503.34 keV at 99.9% intensity" for Pd-103.
Although I am not a nuclear physicist, I think the value in the table
refers to a difference between energy levels and not to electron
emissions. For a radionuclide which decays by EC, almost all of the
energy of the decay process will be given to the emitted neutrino. For
Pd-103, there will be no emission of electrons with an energy of 503.34
keV (and this is not claimed by the table).
I have no reason to believe that the table is wrong.
Regards,
Arvic Harms
> -----Original Message-----
> From: NIXON, Grant (Kanata) [mailto:GNIXON@MDS.Nordion.com]
> Sent: 07 July 2003 15:03
> To: 'Arvic Harms'; 'Mitchell Davis'; Radsafepost
> Subject: Gamma Energies online: a cautionary tale
>
>
>
> I too have consulted the reference you provide.
> Unfortunately, I have found
> what I perceive to be serious errors in the tabulated data. I
> will provide
> an example and reference.
> Consider Pd-103:
> http://nucleardata.nuclear.lu.se/NuclearData/toi/nuclide.asp?i
> ZA=460103
>
> It lists electron emissions at 503.34 keV at 99.9% intensity.
>
> This radiation is not reported in any other reference I have
> consulted,
> including papers by the brachytherapy experts (Williamson,
> Nath, etc.). I
> have contacted the webmaster many months ago about this
> particular issue,
> and they have not responded or deemed it fit to correct the mistake.
>
> My advise is to avoid using it or only to use it with extreme
> caution (with
> corroborative information from an authoritative but
> independent source).
>
> Grant
>
> -----Original Message-----
> From: Arvic Harms [mailto:Arvic.Harms@npl.co.uk]
> Sent: Monday, July 07, 2003 4:24 AM
> To: 'Mitchell Davis'; Radsafepost
> Subject: RE: Gamma Energies online
>
>
> Dear Mitchell,
>
> You may try http://www-nds.iaea.org/ ,
> http://nucleardata.nuclear.lu.se/NuclearData/toi/radSearch.asp or
> http://www.bnm.fr/bnm-lnhb/NucData.htm
>
> Regards,
>
> Arvic Harms
>
>
> Dr Arvic Harms
> Centre for Acoustics and Ionising Radiation
> National Physical Laboratory
> Queens Road
> Teddington TW11 0LW
> Middlesex
> United Kingdom
>
> E-mail: arvic.harms@npl.co.uk
> Tel ++44 20 8943 8512
> Fax ++44 20 8614 0488
>
>
>
> -----Original Message-----
> From: Mitchell Davis [mailto:radiation@cox.net]
> Sent: 05 July 2003 22:45
> To: Radsafepost
> Subject: Gamma Energies online
>
>
> Friends:
>
> I know I have asked this before but am desperate. Are there any GOOD
> websites to search for isotopes and find the gamma energies and %
> abundance? Perhaps an online or electronic copy of Erhtman-Soyka
> (spelling I'm sure!!)? Thanks for the help.
>
> Mitchell W. Davis, RRPT
> Health Physicist
> 432-697-3523
> 432-349-4824 (Cell)
> radiation@cox.net
>
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