Recent Posts

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1
EPMA (and SEM) Education and Training / Re: Teaching PHA
« Last post by Probeman on August 17, 2017, 09:19:48 pm »
Yes EDS detectors instead of porportional counters in WDS spectrometers are the way to go - allowing complete removal of 2nd order interferences (Ken Moran, Rich Wuhrer work).

Hopefully these solid state detectors in WDS spectrometers won't be affected by gain shifting with different count rates. 

That way we'll be able to use PHA discrimination effectively. In the meantime, the interference correction works well.
2
Probe for EPMA / Re: PFE and Windows compatibility (Win7 and Win 8)
« Last post by John Donovan on August 17, 2017, 01:38:14 pm »
I've had a primary user what OS they should get (Win 7,8, or 10) for their new laptop for working with PFE. Is PFE compatible for Windows 10?

PFE will work with Win 7, 8 and 10.
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Probe for EPMA / Re: PFE and Windows compatibility (Win7 and Win 8)
« Last post by Andrew Mott on August 17, 2017, 01:04:08 pm »
I've had a primary user what OS they should get (Win 7,8, or 10) for their new laptop for working with PFE. Is PFE compatible for Windows 10?
4
EPMA (and SEM) Education and Training / Re: Teaching PHA
« Last post by Probeman on August 17, 2017, 09:17:48 am »
Hi Ben,
What exactly do you mean by the peak labeled "X-ray continuum" in the Zr metal?

I wonder if that peak in the Zr metal isn't also a Hf La peak?  The peak in the Zr metal is shifted slightly to the right compared to the HfO2 scan, but that would make sense since the high count rate in the HfO2 would shift the peak to the left compared to a low count rate.  I suspect that commercially available Zr metal has some Hf in it (except for nuclear grade Zr).  They are difficult to separate chemically.

I could be wrong...   but try measuring Hf in your Zr metal using the Hf Ma line also.
john
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EPMA (and SEM) Education and Training / Re: Teaching PHA
« Last post by Ben Buse on August 17, 2017, 01:16:34 am »
Hf La & Zf Ka II example - are particularly good on the Jeol/PFE - for unlike on the cameca software the counts are not normalized - giving the double peak - good to demonstrate the principle of PHA

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EPMA (and SEM) Education and Training / Re: Teaching PHA
« Last post by Ben Buse on August 17, 2017, 01:13:59 am »
Yes EDS detectors instead of porportional counters in WDS spectrometers are the way to go - allowing complete removal of 2nd order interferences (Ken Moran, Rich Wuhrer work).
7
Probe for EPMA / Re: Performing Integrated WDS and EDS Acquisition in PFE
« Last post by John Donovan on August 16, 2017, 03:00:10 pm »
I recently modified the EDS acquisition code to utilize a "sample counting time" option. It used to be called a "preset count time" option which utilized the EDS integration time of the EDS software, but Bruker doesn't have an API call for this, and I've personally never seen a good reason for using the EDS software integration time as opposed to a "user specified count time" option which was already there.

So now with this new option the software will automatically calculate how long the WDS elements will take to acquire and simply sets the EDS integration time to that number (minus a correction for deadtime, since the EDS acquisition time is is "livetime" units.



I believe that Karsten Goemann mentioned this as an idea some time ago and I only just gotten around to implementing it because I finally managed to think of a reasonable method to get it working.    :-[

Anyway, it's all working now. Update from the Help menu and give it a whirl!
john
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Probe for EPMA / Re: Wish List for PFE Features
« Last post by Probeman on August 16, 2017, 10:15:43 am »
Hi John,

The MAN errors are very nice.

At the moment these are count stats (approximately square root of counts) right? I wonder if it is better to use count stat error or the standard deviation. If people collect multiple points per standard for the MAN backgrounds then the standard deviation of the points is more representative - or maybe a choice?

Ben

Hi Ben,
Yes, they are the square root of the raw intensities, so a 1 sigma variance.

Yes, the standard error would be more appropriate since these are usually the average of several points, but well, no one seems to utilize standard errors even when they should!

I once asked a statistics person why don't people use the standard error rather than the standard deviation for the variance of the average and he said: "I don't know, maybe because it's a more conservative number?"

I normally acquire at least 3 data points on each standard (including MAN standards), but others may not, so the variance is a safe bet to display.
john
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Probe for EPMA / Re: Performing Integrated WDS and EDS Acquisition in PFE
« Last post by John Donovan on August 16, 2017, 08:57:39 am »
Attached (please login to see attachments) is my 2016 EPMA Topical Conference talk (Madison, WI) on integrated EDS-WDS with Thermo and Bruker systems.
john
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Probe for EPMA / Re: Wish List for PFE Features
« Last post by Ben Buse on August 16, 2017, 06:04:24 am »

Hi Anette,
Finally got around to implementing errors bars for the MAN fit dialog in PFE (as usual please use the Help menu to update):



This plot is interesting because it shows that all the MAN standards have zero Na within variance, except for the K-411 glass (#162), which I've determined using off peaks is around a couple hundred PPM... so technically, it should be removed from the fit.

Sorry this feature took so long.  I've been busy!   :)

Hope M&M is going well.  Have you presented the TDI Scanning poster yet?
john

Hi John,

The MAN errors are very nice.

At the moment these are count stats (approximately square root of counts) right? I wonder if it is better to use count stat error or the standard deviation. If people collect multiple points per standard for the MAN backgrounds then the standard deviation of the points is more representative - or maybe a choice?

Ben
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