Long Arbitrarily Oriented Traverses

[glennpoirier]

Hi All,
I'm trying to acquire some long closely-spaced traverses across growth zones in Mn nodules. I've done this before using very thin quant maps, but unless I'm missing something, you can't do strip maps that are at an arbitrary angle to the X or Y axes. I was thinking that I could just do parallel long traverses, but there's a problem there too. I want to use really short counting time (ca. 1s) so the spectrometer move times will add a significant multiplier to the analysis time. Ideally I'd like to measure the first five elements over the whole traverse and then come back and repeat the points for the second 5 elements. Is this possible in PfE? I couldn't find a switch for this.
What I think I'm going to have to do is make two different sample setups  and run the traverse once for each setup. Then I can use the Combine Selected Samples button to combine them for the matrix correction.
Can anyone verify that this is the easiest way to do this, or am I missing something?

Have a great weekend
Glenn

[Probeman]

Hi All,
I'm trying to acquire some long closely-spaced traverses across growth zones in Mn nodules. I've done this before using very thin quant maps, but unless I'm missing something, you can't do strip maps that are at an arbitrary angle to the X or Y axes. I was thinking that I could just do parallel long traverses, but there's a problem there too. I want to use really short counting time (ca. 1s) so the spectrometer move times will add a significant multiplier to the analysis time. Ideally I'd like to measure the first five elements over the whole traverse and then come back and repeat the points for the second 5 elements. Is this possible in PfE? I couldn't find a switch for this.
What I think I'm going to have to do is make two different sample setups  and run the traverse once for each setup. Then I can use the Combine Selected Samples button to combine them for the matrix correction.
Can anyone verify that this is the easiest way to do this, or am I missing something?

Have a great weekend
Glenn

Hi Glenn,
There are at least a couple of possible ways to proceed here.

1. You could certainly set up two separate point traverse setups in Probe for EPMA each with 5 elements (to save spectrometer motion time) and then, as you mentioned, utilize the Combine Selected Samples button to obtain a complete analysis.  That might be how I proceed.

2. Aside from rotating the sample to an orthogonal orientation in the stage holder, maybe JEOL has a map acquisition method to acquire a pixel mapping scan line at an arbitrary angle (though Probe Image does not), so then you could acquire your scan line that way and then to quantify it, utilize the conversion utility in Probe Image to convert the JEOL scan line map into the PrbImge format for subsequent quantification in CalcImage.

Alternatively you could specify a polygon mapped area using the JEOL software (which I know works), that delineates a diagonal strip across your Mn nodule.  And then, once again, utilize the convert utility in Probe Image to convert your JEOL map to a PrbImg file for subsequent quantification in CalcImage.

Finally it should be mentioned that if you do obtain a single pixel wide diagonal scan line map using the JEOL (or Cameca software) and want to subsequently quantify that in CalcImage, that is fine, but you will not be able to output the data using Golden Software's Surfer app as Surfer GRD files must be at least 2 pixels wide. For (orthogonal) single scanline maps, you would need to convert them to a 2 pixel wide scan as described here:

https://probesoftware.com/smf/index.php?topic=1154.0

I'm sure I've completely overlooked other methods, but that is my first thoughts on the question...

[glennpoirier]

Hi John,
Thanks for the detailed response. I think in the end I'll use one of JEOL's cup holder and fix the sample to the top. It will allow fairly simple rotation but it will  need a bit of futzing to get the orientation right (I'll probably get the shop to make me something easier to adjust).
A new question arises though.  The sample top is at Z = 12.65 and ProbeImage doesn't like this number. Where is probe image getting its stage limit numbers?

Cheers
Glenn

[John Donovan]

A new question arises though.  The sample top is at Z = 12.65 and ProbeImage doesn't like this number. Where is probe image getting its stage limit numbers?

In Probe Image click the Setup | Probe Image Setup menu, Stage/Spectro Extents button.

[glennpoirier]

Nevermind, found it. (Setup->  Probe Image Setup > Instrument > Stage/Spectro) Was looking for a config file.
Cheers
Glenn

[Anette von der Handt]

Hi Glenn,

a note of caution with the 1 second count time. In my experience there is sometimes a lag with the detector recording the X-ray counts in the first second. I had that on my 8900 and now on the 8530FPlus and I know of at least one other JEOL instrument. It really only comes out in 1 second measurements but maybe you have seen it in TDI measurements where occasionally the first point is 50% lower than the following counts.

You can often check it also by running the chart recorder, open the PCD and see how long it takes for the different spectrometers to register the counts (in my experience the time lag also differs between the spectrometers).

One way around is to set a 1 second incubation delay for the analyses if you find a similar behavior on your instrument.

[glennpoirier]

Hi Annette,
Thanks for the info. In the end I decided that this wasn't the approach I would take. I found that the overhead time per pixel was too high (this may be something I could bring down by playing with acquisition settings, project for later maybe).
In case any one else needs to do this here's how I ended up doing the strips:
By taping the slide to the JEOL cup holder with double sided Kapton tape and adjusting the angle til I got the long axis of my selected traverse  parallel to the Y axis (usually took a couple of tries; I'm going to get the shop to make me a modified holder with a rotating table for the next time I do this).



Due to a probable problem with the JEOL stage (that I still can't figure out ) I wasn't able to use Probe Image to acquire  long thin strips in the Y direction  (PI worked fine in the X direction but I wanted to minimize small stage movements). I ended up using the JEOL mapping software to acquire sequential 8 x 2000 strips. Using the conversion tool in Probe Image (which worked really well!) I imported the strips into CalcImage and produced the quant maps. The client is quite pleased with the results.

[John Donovan]

Due to a probable problem with the JEOL stage (that I still can't figure out ) I wasn't able to use Probe Image to acquire  long thin strips in the Y direction  (PI worked fine in the X direction but I wanted to minimize small stage movements). I ended up using the JEOL mapping software to acquire sequential 8 x 2000 strips. Using the conversion tool in Probe Image (which worked really well!) I imported the strips into CalcImage and produced the quant maps. The client is quite pleased with the results.

Glenn and I have discussed this off-line with Anette, because what Anette found on her 8530 was that she was able to perform the thin strip acquisition using Probe Image that failed on Glenn's 8230. At this point our best guess is that his stage is causing a timeout error that the JEOL software ignores but that Probe Image traps.

[John Donovan]

Nevermind, found it. (Setup->  Probe Image Setup > Instrument > Stage/Spectro) Was looking for a config file.
Cheers
Glenn

Glenn,
It occurs to me that your stage limits might be too close to your map scan width. Try setting the stage limits a little wider in the Probe Image config dialog and see if that affects anything.