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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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