General EPMA > EPMA Standard Materials

Promethium standard material

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orlandin:
Hello, all!

This may seem obvious to many of you but I am struggling to find a promethium-bearing standard. I am no nuclear chemist, but it seems like there may be some good reasons for that. Before giving up on my search and telling the client that it's okay to not measure this because nobody else can measure it either, I wanted to see if anyone here has a good source for a Pm standard.

Best,

Phil

Probeman:
Well it seems to me that this is an obvious situation for the use of the "virtual standard" feature in Probe for EPMA:

https://probesoftware.com/smf/index.php?topic=179.0

On a JEOL LiF spectrometer, Pr is calculated to be:

Spectro position for pr la on LIF (140 mm), is 171.2667 (without refractive index correction)

That puts it just between Ce and Nd as seen here:

Spectro position for ce la on LIF (140 mm), is 178.1162 (without refractive index correction)
Spectro position for nd la on LIF (140 mm), is 164.8277 (without refractive index correction)

So as long as you have the Smithsonian (or other) REE phosphate standards this will be easy to do.

crystalgrower:
Well I’ll be hornswoggled.  Here I thought that since Pm falls between Nd and Sm, I would expect the X-day spectrum to be located there too—see attached. 

Since all isotopes of Pm are radioactive, the  most sensitive method is using  a gamma spectrometer.   The reference spectra for all three isotopes have been published.   You must  match  multiple peak energies and heights to a reference spectrum to report a positive ID.  But you don’t need an actual  piece of Pm.
Solid Pm would be sold in the form of Pm2O3 or PmF3 or PmPO4 NOT the metal which oxidizes quickly.  A Pm tracer would be sold as the PmCl3 solution to avoid redox issues.  Check your local regulations for the paperwork you must submit to purchase.   

A good look at the Wikipedia article will identify  many other facts to discuss with specific customers.    Pm sticks to  particles and therefore not be uniformly distributed.
There should be plenty of published data on Pm in air filters after nuclear fires.  You have to count the filters for up to 100 hours to confirm the absence. 

Probeman:

--- Quote from: crystalgrower on March 05, 2022, 09:48:22 AM ---Well I’ll be hornswoggled.  Here I thought that since Pm falls between Nd and Sm, I would expect the X-day spectrum to be located there too—see attached. 

--- End quote ---

Ooops.    :-[

Sorry, mistook Pr for Pm. So for Pm, just use the virtual standard feature in Probe for EPMA using the Nd and Sm lines:

Spectro position for nd la on LIF (140 mm), is 164.8373 (with refractive index correction, k= 0.000058)
Spectro position for sm la on LIF (140 mm), is 152.9739 (with refractive index correction, k= 0.000058)

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